Aleteia logoAleteia logoAleteia
Monday 27 June |
The Blessed Virgin Mary, Our Lady of Perpetual Help
Aleteia logo
Art & Culture
separateurCreated with Sketch.

Latin 101: (Almost) every phrase you need to know to get by in English


George Edward Robertson - Public Domain

John Burger - published on 10/21/19

Our language is liberally sprinkled with Latin phrases. Do we know what they mean, and are we using them correctly?

The Latin language has had an outsized influence on languages all over the world. It’s no wonder, since the Romans, in their empire building, left it all over the Mediterranean world. And many explorers to the New World and the Indies were people who spoke Latinate languages—Spanish, Portuguese and French.

Not to mention the influence of the Latin (Roman) Catholic Church.

Today, it’s almost impossible to speak for a few minutes without including some Latin-based word or expression. And many terms in law, medicine, philosophy and other disciplines are straight out of the language of the Romans.

Here’s a modest guide to some of the major Latin words and expressions, with special attention to those that are sometimes most misunderstood or misused by modern American speakers.

A contrario

Equivalent to “on the contrary” and “au contraire.” An argumentum a contrario (“argument from the contrary”) is an argument or proof by contrast or direct opposite.

Ad absurdum

In logic, to the point of being silly or nonsensical. Not to be confused with ab absurdo (“from the absurd”).

Ad astra per aspera

“To the stars through difficulties.”

Ad hoc

Generally means “for this,” in the sense of improvised or intended only for a specific, immediate purpose. It’s usually used to refer to an ad hoc committee.

Ad hominem

“At the man.” An argumentum ad hominem is a logical fallacy consisting of criticizing a person when the subject of debate is the person’s ideas or argument, on the mistaken assumption that the soundness of an argument is dependent on the qualities of the proponent.

Ad infinitum

Enduring forever. Used to designate a property that repeats in all cases in mathematical proof. Also used in philosophical contexts to mean “repeating in all cases.”

Ad lib

Comes from the phrase ad libitum, meaning “toward pleasure,” “according to what pleases” or “as you wish.” Libitum comes from the past participle of libere, “to please.” In music, for example, someone “ad libbing” is improvising.

Ad litem

Literally, “to the lawsuit,” this legal phrase refers to a party appointed by a court to act in a lawsuit on behalf of another party who is deemed incapable of representing himself. An individual who acts in this capacity is called a guardian ad litem.

Ad majorem Dei gloriam

“For the greater glory of God,” the motto of the Society of Jesus, often abbreviated AMDG.

Ad multos annos

“To many years.” A wish for a long life; similar to “many happy returns.”

Ad nauseam

“To the point of disgust.” This phrase sometimes is used as a humorous alternative to ad infinitum. An argumentum ad nauseam is a logical fallacy whose erroneous proof is proffered by prolonged repetition of the argument, i. e., the argument is repeated so many times that persons are “sick of it.”


An item to be added, especially as a supplement to a book. The plural is addenda.

Alma mater

Literally “nourishing mother,” this term is used for the university one attends or has attended.

Amicus curiae

A “friend of the court,” an adviser, or a person who can obtain or grant access to the favor of a powerful group, e. g., the a Roman Curia. In current U.S. legal usage, an amicus curiae is a third party allowed to submit a legal opinion in the form of an amicus brief to the court.

Anno Domini

“In the year of the Lord.” The initials always come before the year, e.g., “Augustus died in AD 14.”

A posteriori

“From the latter.” Based on observation, i. e., empirical evidence; the reverse of a priori. Used in mathematics and logic to denote something that is known after a proof has been carried out. In philosophy, used to denote something known from experience.

A priori

“From the former.” Presupposed independent of experience; the reverse of a posteriori. Used in mathematics and logic to denote something that is known or postulated before a proof has been carried out. In philosophy, used to denote something is supposed without empirical evidence. In everyday speech, it denotes something occurring or being known before the event.

Ars gratia artis

“Art for art’s sake.” If you’re the kind of person who likes to watch a movie from the absolute beginning to the very end, you may have noticed this motto on the MGM logo, when the lion roars. Wikipedia, however, says that the better word order in Latin is Ars artis gratia.

Bona fide

“In good faith.” In other words, “well-intentioned.” In modern contexts, this often has connotations of “genuinely” or “sincerely.”

  • 1
  • 2
  • 3
Support Aleteia!

Enjoying your time on Aleteia?

Articles like these are sponsored free for every Catholic through the support of generous readers just like you.

Thanks to their partnership in our mission, we reach more than 20 million unique users per month!

Help us continue to bring the Gospel to people everywhere through uplifting and transformative Catholic news, stories, spirituality, and more.

Support Aleteia with a gift today!

Daily prayer
And today we celebrate...

Entrust your prayer intentions to our network of monasteries

Top 10
See More
Get Aleteia delivered to your inbox. Subscribe here.