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ad hoc

Created when necessary for a specific purpose (as opposed to being planned or prepared in advance). The phrase is Latin for "to this." Let's form an ad hoc committee to make some recommendations to the board, and then we'll decide how to address this issue. Ad hoc wireless networks often present security risks to unsuspecting mobile device users.
See also: ad, hoc

ad in

In tennis, a shortening of "advantage in," meaning the server has the advantage and will win the next point after deuce. The score is ad in because Tiffany is serving, and she has the advantage.
See also: ad

ad infinitum

Continuously without end. The phrase is Latin for "to infinity." Repairs to the old house seemed to go on ad infinitum—every time we finished a project, another awaited us.
See also: ad

ad nauseam

Continuously and to excess. The phrase is Latin for "to nausea" (to the point that one becomes ill). I couldn't help but check my watch as Beth talked ad nauseam about her boyfriend's accomplishments.
See also: ad

ad out

In tennis, a shortening of "advantage out," meaning that the player who is receiving has the advantage and will win the next point after deuce. The score is ad out because Tiffany is serving, and she does not have the advantage.
See also: ad, out


1. adjective Of or characterized by an impromptu fashion, with little or no preparation beforehand. Jazz improv is always a bit ad-lib by design; you can't plan what you might play!
2. adverb Done in an impromptu or free-hand fashion, with little or no preparation beforehand. His comedy is always so unique; I hear he does the whole thing ad-lib.
3. noun Something, usually performative in nature, that is done with little or no preparation beforehand. His speech this morning felt like it was a bit of an ad-lib. I don't think he prepared any notes ahead of time.
4. verb To say, do, or perform something in an impromptu fashion, with little or no preparation beforehand. I had forgotten to rehearse my lines for the audition, so I just decided to ad-lib the whole way through.


An initialism for "automated decision support," software that aids decision-making, as via algorithms. Management thinks this new ADS will save us a lot of time, but I'm skeptical.
See also: AD

I approve this message

1. A standard phrase attached to the end of a political advertisement by a candidate running for federal office. Do you really want your future in the hands of someone who launders money for the cartel? Vote Smith-Robertson for president this election. I'm Jonathan Smith, and I approve this message.
2. Used alongside humorous statements in order to parody the solemnity of the message. A: "I say you need to eat more vegetables. I'm your father, and I approve this message!" B: "Har har, Dad."
See also: approve, message, this

reductio ad Hitlerum

An argument that compares someone or something to Adolf Hitler or Nazism, usually as an attempt to nullify the debate or debater. The phrase is modeled on the names of classic logical arguments (e.g. reductio ad absurdum) and is pseudo-Latin for "reduction to Hitler." A: "And anyone who supports that guy is a Nazi!" B: "Geez, it's a little early for reductio ad Hitlerum, don't you think?"
See also: ad
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

ad hoc

For the special purpose or end at hand; also, by extension, improvised or impromptu. The term, Latin for "to this," is most often used for committees established for a specific purpose, as in The committee was formed ad hoc to address health insurance problems. The term is also used as an adjective ( An ad hoc committee was formed), and has given rise to the noun adhocism for the tendency to use temporary, provisional, or improvised methods to deal with a particular problem. [Early 1600s]
See also: ad, hoc

ad nauseam

To ridiculous excess, to a sickening degree. For example, I wish he'd drop the subject; we have heard about budget cuts ad nauseam. The term, Latin for "to [the point of] nausea," has been used in English since the early 1600s.
See also: ad
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

ˌad ˈhoc

(from Latin) arranged or happening when necessary and not planned in advance: The meetings will be held on an ad hoc basis.
See also: ad, hoc

ˌad infiˈnitum

(from Latin) without ever coming to an end; again and again: You cannot stay here ad infinitum without paying any rent.The problem would be repeated ad infinitum.
The meaning of the Latin phrase is ‘to infinity’.
See also: ad

ˌad ˈnauseam

(from Latin) if a person says or does something ad nauseam, they say or do it again and again so that it becomes boring or annoying: Television sports commentators repeat the same phrases ad nauseam.
The meaning of the Latin phrase is ‘to sickness’.
See also: ad
Farlex Partner Idioms Dictionary © Farlex 2017
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