# ad hoc

idiom · CEFR B2

Source: https://englishreference.com/idiom/ad-hoc
Updated: 2026-08-03

## Meaning

Made for this one situation, with no general rule behind it.

## Examples

- 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.

## Origin

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.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.