ad hoc
Made for this one situation, with no general rule behind it.
“We set up an ad hoc group to deal with it.”
“Decisions were being made on an ad hoc basis, which worked until two of them contradicted each other.”
“What the audit found was not a bad policy but the absence of one: a decade of ad hoc exceptions, each defensible on the day it was granted and indefensible as a set.”
Ad hoc means for this — for this thing, this case, this occasion, and nothing else. It is ordinary classical Latin, and it entered English in the seventeenth century as a technical term for arrangements made to handle one matter only.
The neutral use survives: an ad hoc committee is simply one formed for a single question and dissolved when the question is answered, as opposed to a standing committee that meets whatever happens.
The other use is a criticism, and it came from philosophy of science. An ad hoc hypothesis is one invented purely to save a theory from a fact that contradicts it — it explains the one awkward case and predicts nothing else. That sense has spread into everyday English, where calling a solution ad hoc means it works here and will not survive contact with the next case.
Roman legal Latin that never left the courtroom — or the boardroom.
- 01
bona fide (idiom)
Genuine and honestly meant — the real thing, not a pretence.
The Roman standard of good faith.
- 02
caveat emptor (idiom)
Let the buyer beware — checking what you are buying is your own problem.
What Rome did not actually say.
- 03
quid pro quo (idiom)
Something given in return for something else, usually as an understood trade.
From the apothecary's substitute.
- 04
de facto (idiom)
In practice, whatever the official position says.
The question of fact.
- 05
de jure (idiom)
According to the law, whether or not that is what actually happens.
The question of law.
- 06
ipso facto (idiom)
By that very fact — the consequence follows automatically, with no further step.
Consequences that need no hearing.
Last updated August 3, 2026