From Longman Dictionary of Contemporary Englishone-offˈone-off1 adjective [only before noun] British English ONLYhappening or done only once, not as part of a regular series SYN one-shot American English It’s yours for a one-off payment of only £200.
Examples from the Corpus
one-off• Many extremely interesting publications on art currently only exist as a one-off draft.• So far, most discounters have stuck to selling food, though Aldi does use one-off promotions of clothing to attract customers.• In fact the whole exercise was fairly straight forward, except for one problem which required a one-off solution.• They will play a one-off Test and three one-day internationals between March 10-25.• It's the one-off thug who normally panics and lashes out.• Verdict: Recommended for one-off use in conditions where you dare not risk an expensive camera.one-off payment• In addition, a number of one-off payments were made to the Partnerships.• This is a one-off payment which protects the lender in case you default on the loan.one-offˌone-ˈoff2 noun [countable] British English 1 DIFFERENTsomething that is done or made only once The deal was a one-off.2 informalDIFFERENT someone who is completely different from anyone elseExamples from the Corpus
one-off• Ever since 1959, and Bomb, Miles had been experimenting with small magazines and one-offs.• Some were marked as regular orders, some as one-offs. 