53 Must-Know Latin Phrases Used in English: learn them now!
Latin may be a “dead” language, but Latin phrases are still used all the time in modern English. How many of these common expressions do you know?
We all use basic Latin phrases even if we don’t realize it. I guarantee you have said “et cetera” or “vice versa” at least once in your life. And have you ever turned in a curriculum vitae (or C.V.) when applying for a job?
Some Latin expressions slip into English unobtrusively, while others – like mutatis mutandis and cum laude – look a little more foreign. In this post, I will introduce you to over fifty popular Latin phrases that you really should know.
If you don’t, no shame. It’s a chance to learn something new!
Common Latin Phrases Used in English
Are you ready? Here come over 50 awesome Latin words and phrases that appear in English on a regular basis! You don’t need to know any Latin in order to follow along, because I explain both the literal and the idiomatic meaning.
But here’s a quick note for anyone who is learning Latin: since I am focusing on the use of the phrases in English, I have not included macrons in the spelling of the Latin words.
1. A priori & a posteriori
Literal meaning: “from (what comes) first” and “from (what comes) after”
The expressions a priori and a posteriori are primarily used in philosophical or logical contexts. An a priori argument is based on self-evident principles and thus on “what comes first.” A priori arguments move from causes to effects.
An a posteriori argument, on the other hand, is constructed based on reviewing the evidence – that is, “what comes after”. A posteriori arguments move in the opposite direction, from effects or data to causes.
2. Ad hoc
Literal meaning: “to this”
Ad hoc in English means “created for this specific purpose” or “impromptu”. So, if there is a flood in a school, the principal may call an ad hoc meeting to discuss how to respond.
We often hear about decisions made ad hoc, as well. An ad hoc decision is one that is made for the context at hand. You aren’t thinking about the broader significance, but rather of the specific application.
Hoc is a form of the Latin pronoun hic, haec, hoc which means “this” or “these”.
3. Ad hominem
Literal meaning: “to the man”
The most common usage of ad hominem today is to talk about an ad hominem argument. This is an argument that relates “to the man”, i.e. to the person you are arguing with. Instead of addressing the real topic of the debate or the person’s reasoning, you attack their character.
Thus ad hominem arguments are usually irrelevant or illogical. For instance, if you are debating ethics with your friend and you can’t refute their point, you might yell, “You don’t know anything about ethics! You cheated on your final exam in physics!”
Fun Fact: it’s rare, but the term ad feminam also exists. With the literal meaning “to the woman,” this is the female equivalent of ad hominem.
4. Ad infinitum
Literal meaning: “to infinity”
If something continues ad infinitum, this means that it goes on forever, without end. If Buzz Lightyear from Toy Story spoke Latin, he would say, “Ad infīnītum et ultrā!” (To infinity and beyond!)
5. Ad lib
Literal meaning: “to one’s pleasure”
“Ad lib” is short for ad libitum, which is a phrase meaning, loosely, “as much as you want.” According to Etymonline, it was originally a musical notation. In this context, it indicates that the musician could use their own judgment to decide how a piece should be played.
Over time, the phrase shifted to acquire its most well-known meaning: to do something without preparation. In English, we can use “ad lib” as a verb. For example, “I forgot to prepare for my oral exam so I had to ad lib everything!”
6. Ad nauseam
Literal meaning: “to nausea, to vomiting”
If you do something ad nauseam, this means that you do it to a nauseating degree. For example: “We have discussed your ingrown toenails ad nauseam. Let’s change the subject!”
My Latin students likely think that I talk about using flashcards ad nauseam. But hey, flashcards are a great way to learn vocabulary!
7. Alias
Literal meaning: “at another time, in other circumstances”
Alias is an adverb in Latin, but in English we most frequently use it as a noun. An alias is a fake name or assumed identity. For example, Superman is Clark Kent’s alias.
“Alias” can also be used as an adverb in English to indicate someone’s more familiar name. In this case, it is equivalent to the English “aka” or “also known as.” To return to our previous example, you could say, “Clark Kent, alias Superman, saved many people.”
8. Alibi
Literal meaning: “elsewhere”
“Alibi” is a great example of a Latin word used so frequently in English that we don’t even recognize its foreign origin. In fact, alibī is a Latin adverb meaning ”elsewhere”.
This makes sense since in modern English, an alibi is evidence that can prove that you were elsewhere when a crime was committed. ”I can’t have stolen the diamond necklace, because I was somewhere else – I was at school during the robbery and my teacher will tell you so!”
(And yes, if you are wondering – alias and alibi are etymologically related.)
9. Alma mater
Literal meaning: “nurturing mother”
The Latin adjective alma means “nurturing” and often described fertility goddesses in ancient Rome. In the 1700s, people started referring to their university as their alma mater. It makes sense – your university is the mother who nourishes your intellectual growth!
10. Alter ego
Literal meaning: “another I”
The expression alter ego is used so frequently in English that people often don’t realize it is Latin. In fact, alter ego originally referred to a trusted friend. Aristotle, Cicero, and other ancient authors insist that a true friend is so close that they are another self.
Over time alter ego came to have an expanded meaning. Now an alter ego can refer to a person’s hidden identity, to a fictional character who is a double of the author, and more. Clark Kent and Superman, Dr. Jekyll and Mr. Hyde – the list goes on.
11. Anno Domini (A.D.)
Literal meaning: “in the year of the Lord”
In the modern world we divide time into two eras: an old era before Jesus Christ’s birth and a new era including the year of Christ’s birth (year 1) and all years after. Traditionally, all the years from 1 onward were accompanied by the abbreviation A.D.
So we are currently in A.D. 2024. That is, we are in the 2024nd year since the birth of the Lord.
These days we often hear C.E. or Common Era instead of A.D. and anno Domini. But it is still good to know where the system came from!
12. Ante bellum
Literal meaning: ”before the war”
Today we most frequently see ante bellum written as one word, ”antebellum”, and used as an adjective. In the United States, you may hear about the Antebellum South – i.e., the American South before the Civil War.
The opposite of antebellum is postbellum or ”postwar”.
13 and 14. Ante meridiem (A.M.) & post meridiem (P.M.)
Literal meaning: “before noon” and “after noon”
A.M. and its opposite P.M. are everywhere in the modern world. Most people probably don’t realize, though, that these popular abbreviations are short for ante meridiem and post meridiem. These Latin phrases mean literally ”before noon” and ”after noon”.
👉 Speaking of abbreviations . . . check out my list of Latin abbreviations everyone should know!
15. Bona fide
Literal meaning: “in good faith”
In modern English, bona fide is usually an adjective meaning “genuine” or “authentic”. A bona fide genius is someone who is, literally, a genius (not just a relatively smart person who gets called a genius).
We also hear of bona fide offers, proposals, etc. Bona fide is occasionally an adverb; for example, “The merchant acted bona fide, but he still lost the goods.”
16. Caveat
Literal meaning: “let him beware”
A caveat is a warning or stipulation. So, for example, I could say: “I highly recommend traveling to Italy, with the caveat that it may be quite hot in the summer.”
A frequent use of caveat is in the phrase caveat emptor, “let the buyer beware.” The idea is that you should be careful when you are making a purchase – you need to check the quality yourself, because the seller might not be honest.
If you are learning Latin, it may interest you to know that caveat is an example of a jussive subjunctive.
17, 18, and 19. Cum laude, magna cum laude, & summa cum laude
Literal meaning: “with honor”, “with great honor”, and “with greatest honor”
Many universities award high-achieving students with Latin honors. If you graduate with a high grade point average (G.P.A.), then you will receive a bachelor’s degree cum laude, magna cum laude, or summa cum laude.
Different universities have different scales for Latin honors. At my undergraduate institution we had the following range:
- Cum laude: G.P.A. of 3.40 and above
- Magna cum laude: G.P.A. of 3.70 and above
- Summa cum laude: G.P.A. of 3.90 and above
20. Curriculum vitae
Literal meaning: “course of life”
Your curriculum vitae or C.V. documents your education, jobs, qualifications, and accomplishments. It is, in effect, a record of your life – so the original Latin meaning makes sense.
21 and 22. De facto & de jure
Literal meaning: “in fact” and “by law”
De facto is used to describe a state of affairs that exists in reality, even if it is not legally sanctioned. Someone might be the de facto head of the government, even if they technically are only an advisor to the president. Or a country might be in a de facto state of war, even if neither side is willing to recognize it.
De jure, on the other hand, refers to the situation as recognized by law. In our previous example, the president is the de jure head of the government, even though their advisor is actually the one in control.
23. Deus ex machina
Literal meaning: ”god from a machine”
A deus ex machina is a person or thing that appears suddenly in a literary work in order to solve an otherwise unsolvable problem. In ancient Greek plays, a god or goddess would often make an appearance at the end of a play in order to explain what should happen or what the characters ought to do.
In ancient Greece, the actor playing the divinity would be rolled onto the stage on a crane called a mechane. And this is what gave us the expression “god from the mechane” or “god from a machine”.
24. Dramatis personae
Literal meaning: ”characters of the drama”
Have you ever read a play of Shakespeare, or any play script? Then you may have encountered the phrase dramatis personae. The English equivalent is ”cast of characters”.
The dramatis personae includes each character’s name along with a brief description of who they are.
25. Ergo
Literal meaning: “therefore”
We have borrowed ergo straight from Latin and we use it in exactly the same way as the ancient Romans did: to mean “therefore”. Of course, saying “ergo” in English can make you sound kind of stuffy and pedantic.
26. Et cetera
Literal meaning: “and other things”
Et cetera is one of the most common Latin phrases used in English. Since it literally means “and other things”, we usually find it at the end of lists or long descriptions.
27. Habeas corpus
Literal meaning: “may you have the body”
A writ of habeas corpus is a court order that requires a jailer to bring a detained person before the court. Habeas corpus is meant to prevent false imprisonment; any detained person can petition for a writ of habeas corpus to be issued on their behalf.
According to Etymonline, the Latin phrase itself comes from a 14th-century law. The full law says something to the effect of “we command that you bring the body before us.”
If you are learning Latin, habeās is a good example of the present subjunctive of 2nd conjugation Latin verbs. Notice the –ea– vowel sequence; we also saw it in caveat earlier in this post.
28. In loco parentis
Literal meaning: “in the place of the parent”
The Latin phrase in loco parentis is used to refer to someone who has some of the responsibilities or functions of a parent. For instance, if a child is raised primarily by their grandmother, we might say that said grandmother acts in loco parentis.
29. In memoriam
Literal meaning: ”in memory”
This phrase is pretty self-explanatory. We dedicate books, movies, fellowships, etc. in memory of our deceased loved ones, and often we write in memoriam on the program or include it in the title.
30. In situ
Literal meaning: “in the place / location”
In situ is used in many different fields, from archaeology to medicine to engineering. The phrase emphasizes that something exists in its original location or that an action is carried out on site.
Since I have participated in excavations in Italy and Turkey, I am most familiar with the archaeological sense. Let’s say you are excavating and you uncover the ruins of a wall. You decide that the wall is important enough to leave in situ: that is, you leave the wall where you found it, exactly as it has survived for centuries.
In oncology, in situ refers to abnormal cells that have not spread beyond the spot where they originally formed. A tumor in situ is equivalent to stage 0 disease, since the abnormality has not spread to surrounding tissue.
Finally, if engineers talk about assembling something in situ, that means that they will put the object together at the construction site.
These representative examples give you an idea of what to expect when you stumble across in situ in your everyday life!
31. In vitro
Literal meaning: “in a glass”
In vitro is used to describe a process that takes place in a test tube, Petri dish, or other environment outside of a living organism. The most well-known use is in the term “in vitro fertilization”, but scientists can carry out many kinds of experiments in vitro.
32. Ipso facto
Literal meaning: ”because of the deed itself, by the very act”
Ipso facto in English means ”inevitably” or ”necessarily”. If something is true ipso facto, then it is true by definition, without a doubt.
33. Magnum opus
Literal meaning: “great work”
A magnum opus is a creative masterpiece, whether of art, music, or writing. It often refers to an artist or author’s best and/or most famous work.
For instance, we could say that Leo Tolstoy’s magnum opus was the novel War and Peace.
34. Mea culpa
Literal meaning: “(through/by) my fault”
Mea culpa is a way of taking blame for something or saying you are sorry. The phrase comes from the Catholic Confiteor or prayer of confession, where the speaker admits that they have sinned through their own fault.
Nowadays there isn’t necessarily a religious element to mea culpa, and I have heard many people use this Latin phrase in a secular context. For example, one of my Latin students might say: “Mea culpa, I forgot to study my verb principal parts!”
35. Mutatis mutandis
Literal meaning: “with things having been changed that ought to be changed”, i.e. “with the necessary changes having been made”
I debated whether or not to include mutatis mutandis in this list of common Latin phrases, because it is a little rarer. But it shows up just enough in academic and legal contexts that it deserves a mention.
Typically, we use mutatis mutandis in order to recognize that a comparison is not perfect, but still has some validity. So, for instance, I could say, “The experience of traveling in Italy is, mutatis mutandis, quite similar to that of traveling in Spain.”
Or we can use mutatis mutandis to signal that something will work well once the necessary changed have been made. For example: “I think that we should move forward with the new contract, mutatis mutandis.”
36. Non sequitur
Literal meaning: “it does not follow”
Non sequitur is one of the most familiar Latin phrases still found in English today. Back in the 1500s, the term began to be used in logic to refer to a conclusion that did not follow from the premise.
Now the meaning has broadened. We can say any sort of statement is a non sequitur if it doesn’t relate to the rest of the conversation. Let’s say you are talking about reading Latin novellas and your friend suddenly says, “But I really like swimming with sea turtles!” That would be a non sequitur.
This phrase comes from the common Latin deponent verb sequor, which means “follow.” This is also where we get words like sequence and consecutive.
37. Nota bene
Literal meaning: “note well”
Nota bene, abbreviated to N.B., appears frequently in academic articles, textbooks, etc. Authors use it to draw readers’ attention to something specifically important.
For example, if you were drafting an instruction manual to a microwave, you might write: “Nota bene: do not put anything metal in the microwave!”
Fun Fact: Nota Bene is the name of the Harvard Classics newsletter. In the Commencement 2023 issue, you can see my graduation announcement on page 11 and my account of a trip to Rome on page 23!
38 and 39. Per annum & per diem
Literal meanings: “per year” and “per day”
These two basic Latin phrases often pop up in English in the context of hours or pay. For instance, you may earn a certain amount per annum (per year). Or percentages may increase a certain amount per diem (per day).
A per diem can also refer to the allowance that an employer gives their employees per day when traveling. In this case, per diem is a noun.
Per is a common Latin preposition, so you will run into it often now that you are paying attention!
40. Per capita
Literal meaning: “per heads”
In a modern context, per capita means “per unit of population”. We can talk about deaths per capita, jobs per capita, income per capita, etc.
41. Per se
Literal meaning: “through itself”
Per se is another extremely common Latin phrase. The easiest way to translate it into idiomatic English would be “in and of itself” or “intrinsically”.
So, for example, I could say: “I don’t think a focus on grammar is bad per se, but it is often accompanied by old-fashioned and harmful teaching methods.”
42. Persona non grata
Literal meaning: “a not welcome person”
A persona non grata is one who, for whatever reason, is not welcome in a certain place. Example: ”Every since he insulted the emperor, Lucan has been persona non grata in all of the imperial circles.”
43. Pro bono
Literal meaning: “for the good”
This Latin phrase is mostly used in a legal context. Lawyers will do pro bono work – that is, they work for free, for the public good.
44. Quid pro quo
Literal meaning: “something for something”
A quid pro quo transaction is one in which each person contributes something in exchange for something else. Quid pro quo often receives a negative reputation: we think of bribery, underhanded deals, or even harassment.
But technically any trading or exchange can be classed as quid pro quo. If I cut my neighbor’s grass and they give me apple pie in return, then that is a quid pro quo transaction!
45. Requiem
Literal meaning: ”rest”
A requiem mass is a mass said for the souls of the dead. Requiem comes from a line in the mass for the dead: Dōnā eīs requiem ”grant them peace.”
46. Sic
Literal meaning: “thus”
In newspaper articles and other written contexts you will see [sic] inserted in the middle of quotes. Often people think this is an abbreviation, but nope – it’s just a Latin word meaning “thus” or “so.”
Writers use [sic] to indicate that their original source contained a grammatical error. The writer wants to represent the quote accurately, but wants readers to realize that they weren’t the one to make the mistake.
Example: “He wrote that ‘they’re [sic] song was beautiful.'” In this context, the reporter wants you to know that he – the original source – accidentally put they’re instead of the correct their. They’re was in THE ORIGINAL QUOTE, and was not a mistake that the reporter made.
47. Sine qua non
Literal meaning: “without which not”
A sine qua non is something that is absolutely essential. Here are a few examples:
- “Knowledge of Spanish is a sine qua non for an ambassador to Peru.”
- “Sun screen is a sine qua non on any beach vacation.”
- “Finding a good Latin dictionary is a sine qua non for any Latin student.”
48. Status quo
Literal meaning: “state in which”
The status quo is the current state or condition that a person, company, country, etc. finds themselves in – in other words, the existing state of affairs. We often associate the status quo with stagnation or lack of progress, but it doesn’t have to be negative.
49. Sui generis
Literal meaning: “of its own kind” or “of its own class”
This Latin phrase, which is technically a genitive of description, indicates that something is unique or unparalleled. For example, if a book or movie does not fit into any specific category, we could say that it is sui generis.
50. Terra firma
Literal meaning: “firm or solid land”
“Terra firma” is a Latin expression that distinguishes dry land from the ocean and the air. After a long boat ride, for example, you might feel relieved to be back on terra firma.
51. Verbatim
Literal meaning: “according to (individual) words”
If you repeat something verbatim, this means that you repeat it in exactly the same words as it was originally said. ”Verbatim” comes from the Latin verbum ”word” plus the adverbial ending –ātim.
52. Versus
Literal meaning: “toward, turned in the direction of”
Versus is an a Latin adverb that ultimately derives from the Latin verb vertō “turn.” In modern English, “versus” is a preposition meaning “against” or “in comparison to.”
Here’s a quick example. If you want to start a new language but you aren’t sure which one, you might ask me about the pros and cons of learning Latin versus Spanish.
53. Vice versa
Literal meaning: “with the position having been changed”
Vice versa is such a common expression that it doesn’t really require explanation. Basically, if something is true vice versa, then it is also true the other way around.
So, for example, I could say, “He supports me and vice versa.” This means that not only does he support me, but the reverse is also true: I support him.
Should you italicize Latin phrases used in English?
It depends! Both the Chicago Manual of Style (7.53-55) and the MLA Handbook agree that less common Latin phrases should be italicized. So, for instance, you should put mutatis mutandis in italics.
But if a word or phrase has been anglicized and is now familiar enough that it seems like a part of English, you should not italicize. That’s why you usually won’t see expressions like vice versa, et cetera, and pro bono italicized.
There is definitely an element of subjectivity here. How do you decide, for instance, if a word is “familiar” to the average English speaker? The Chicago Manual of Style says that you should look it up in Merriam-Webster’s and if it is there, you don’t italicize.
Final Thoughts
So, how many of these popular Latin phrases used in English did you actually know? Some of them are a bit tough, but I’m sure you recognized at least a few. Let me know how you fared in the comments!
And, while you’re here – have you ever thought about learning Latin? Here are nine reasons why you absolutely should!
If you’ve been wanting to learn Latin but just don’t know how to get started, then check out my ultimate guide to Latin-learning resources. I list a combination of paid and free resources helpful for students of all levels.
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Just re-studying Latin, which was I enjoyed in high school many years ago. Enjoying your site. I am also interested in mythology, so I love that you are as well.
Hi Cassandra, I am so glad to hear you are enjoying my site! Mythology is so much fun, and hopefully you will be able to read myths in Latin soon 🙂
This is an interesting site. Thank you. Long ago I majored in Latin. In high school and college I was taught to decipher Latin, not really read it. (reading and deciphering are different mental processes) But in recent years, I have been teaching myself to read Latin. The resources of the internet, such as your site, have made this hobby of mine possible.
Hi Mike, I am so happy to hear that my site has been helpful! Yes, *reading* Latin is so different than deciphering it, but unfortunately – due to the way Latin is traditionally taught -many students never get past the deciphering. One of my goals is to encourage a more holistic and natural approach to reading Latin.
I really enjoyed this. I take latin right now as a high schooler and We review phrases like this.
I’m so glad you enjoyed the post! 🙂
Hi, Livia. The word CIRCA came up as a Wordle solution (yesterday, 4/28/23, so this is not a spoiler). That caused me to ponder whether “circa” is really an English word, as opposed to Latin. Some googling led me to your site. I posted an extract to an on-line Wordle group I participate in, with credit and a link to your site, of course. Thanks for your help.
I speak three Latin-based languages, French, Spanish, and Italian (some better than others), but I’ve never studied Latin. If you’re not already familiar with it, I’m sure you’d love the book “From Latin to Romance in Sound Charts”, by Peter Boyd-Bowman. It traces the rather regular changes that occurred in Vulgar Latin as it was transformed into French, Spanish, Italian, and Portuguese (as is often the case, poor Romanian got left out).
Hi Lawrence, thanks for stopping by! I am glad I was able to help with your question about “circa.” The Wordle is so much fun, as is the NYT mini crossword puzzle (which occasionally has Latin-related words as well!).
Ooh, thank you for the book recommendation. I have never read it and I will add it to my list. I speak Spanish fluently and I have basic knowledge of French and Italian, so I am always interested in Latin’s development into the modern Romance languages.
Do you have this list in PDF format for download? Hoping to use the phrases as a kind of weekly latin exordium for my reluctant 9th grade latin student.
Hi Mikael, unfortunately I don’t have the list in PDF format at the moment. But perhaps you could either bookmark the page or use the “print to PDF” function? I hope the phrases help increase your student’s enthusiasm for Latin!
I’m not sure if this one fits, but my dermatologist uses “in situ”…
Thanks for the list!
In situ is a fantastic example – thank you, Mike!
The literal meaning is “in the place” or “on the spot”. Dermatology is one context in which it is used; it’s also a very important term in archaeology. If you take a photo of an object in situ, that means that you photograph it in its exact find spot (wherever it came out of the ground during excavation).
Edit: I have added it to the list!
I was puzzled by the ending of verbatim. Then I saw it was medieval.
Hi Ralph, it’s an odd ending with a long history. But at a certain point it became possible to add –tim to nouns to form adverbs, and that’s what happened with verbātim. Examples from Classical Latin are guttātim (“drop by drop”), ostiātim (“from door to door”), generātim (“by kinds”), and tribūtim (“tribe by tribe”).
Since you have de facto, you might want to add de jure.
Great point, Ralph! I have added it!
very useful as an 8th grade student new to latin
I’m so glad you found the list useful, Rob!
is there a way to take a common English phrase and turn it into a Latin phrase?
Hi Rocky, you can translate an English phrase directly into Latin (more or less word-for-word), although sometimes that doesn’t work since languages have different idioms. My recommendation would be that you look at English-Latin dictionaries, which often offer translations for phrases, as well.
Latinitium has digitized Smith and Hall’s English-to-Latin lexicon and you can search it online for free, which is amazing. It is from 1871, so the English vocabulary may be outdated, but it’s still a great resource. (You can also purchase a hard copy, since Bolchazy-Carducci reprinted it in 2000 as Smith’s English-Latin Dictionary.)
There is also Logeion, which has a feature called “Retro” that allows you to search for Greek and Latin equivalents of English words. Note that the Latin is in the section titled “Riddle-Arnold” (from Riddle and Arnold’s lexicon, published in 1847).