Etymology

From one +‎ offCategory:English compound terms#ONEOFF. Probably from foundry work, for which making reusable molds is expensive and expediency makes the rule for molds not to be used only once.

A term long used by artists who are printmakers and sculptors to indicate a unique print or casting. If using traditional edition numbering, a one-off would be a "1/1", which is said, "one of one" meaning the first print in an edition of one.

Pronunciation

• Audio (US):

  (file)

  Category:English terms with audio pronunciation#ONEOFF

• Audio (General Australian):

  (file)

  Category:English terms with audio pronunciation#ONEOFF

Adjective

one-off (comparative more one-off, superlative most one-off)Category:English lemmas#ONEOFFCategory:English adjectives#ONEOFFCategory:English multiword terms#ONEOFFCategory:English entries with incorrect language header#ONEOFFCategory:Pages with entries#ONE-OFFCategory:Pages with 1 entry#ONE-OFF

1. Occurring once, independent of any pattern; one-time.

   Synonyms: unique, singularCategory:English links with manual fragments#ONE-OFF

   The government insisted that the embarrassing loss of the tax records was a one-off event.Category:English terms with usage examples#ONEOFF

   Seeing Halley's Comet is a one-off, once-in-a-lifetime opportunity.Category:English terms with usage examples#ONEOFF

   • 1905, Foundry, volume 50, page 198:

     If such a casting was wanted in a hurry — a one-off job — there would be no question of molding it on a machine.

     Category:English terms with quotations#ONEOFF

   • 2006 September 1, EIU Country Analysis, Malta: Country outlook:

     Moreover, given that recent measures to cut the deficit have been more one-off than of a structural fiscal nature, meeting this debt target is likely only

     Category:English terms with quotations#ONEOFF

   • 2015 May 6, Colin O'Carroll, “Fermanagh woman thought registering a royal baby was a one-off honour... now Princess Charlotte has come along she's done it twice”, in Belfast Telegraph‎, archived from the original on 21 April 2023, retrieved 14 May 2015:

     A County Fermanagh woman has officiated at the formal registration of the birth of Princess Charlotte at Kensington Palace. It's the second time she's been on royal baby duty at the palace as she previously officiated at the registration of Prince George. She said at the time that it was a "one-off" honour, but that has now been disproved with a repeat visit for Princess Charlotte.

     Category:English terms with quotations#ONEOFF

   • 2020 December 16, “Network News: "Robust case" for Fawley branch line reopening”, in Rail, page 14:

     In July, South Western Railway and Network Rail ran a one-off Class 159 to Fawley, to demonstrate the line's viability. [...] A second 'fact-finding' trial passenger train for DfT officials is now proposed.

     Category:English terms with quotations#ONEOFF

2. Special; remarkable; rare; unusual.

   Synonyms: unique, singularCategory:English links with manual fragments#ONE-OFF

   • 2015 May 13, Hunter Skipworth, “BMW to create one-off tribute to 3.0 CSL”, in Evo‎, archived from the original on 26 September 2020, retrieved 14 May 2015:

     BMW is to create a one-off tribute to the iconic 3.0 CSL.

     Category:English terms with quotations#ONEOFF

   • 2024 July 25, Chinomso Sunday, “Celine Dion to Earn $2 Million for Olympic Ceremony Song”, in newscentral.africa‎, archived from the original on 26 July 2024:

     Grammy award-winning singer Celine Dion will reportedly earn $2 million for a one-off performance at the 2024 Olympics.

     Category:English terms with quotations#ONEOFF

Noun

one-off (plural one-offs)Category:English lemmas#ONEOFFCategory:English nouns#ONEOFFCategory:English countable nouns#ONEOFFCategory:English multiword terms#ONEOFFCategory:English entries with incorrect language header#ONEOFFCategory:Pages with entries#ONE-OFFCategory:Pages with 1 entry#ONE-OFF

1. (idiomaticCategory:English idioms#ONEOFF, CommonwealthCategory:Commonwealth English#ONEOFF) Something that is done, created, etc. only once, and often quickly, simply, or improvisationally.

   Near-synonym: stand-aloneCategory:English links with manual fragments#ONE-OFF

   I'll put together a quick one-off as a sample so we can taste the recipe.Category:English terms with usage examples#ONEOFF

   • 2025 June 22, Luke Broadwater, “Trump Picks a Side on Entering the War in Iran, for Now”, in The New York Times‎, →ISSN, archived from the original on 22 June 2025:

     But even as he announced the military operation, he appeared to be rapidly trying to get himself back to the middle by insisting that the strike was a one-off and that he continues to seek peace.

     Category:English terms with quotations#ONEOFF

2. Something unique and remarkable.

   Near-synonym: stand-aloneCategory:English links with manual fragments#ONE-OFF

   It is a one-off; there is nothing else like it.Category:English terms with usage examples#ONEOFF

   • 2017, David Walliams [pseudonym; David Edward Williams], Bad Dad, London: HarperCollins Children’s Books, →ISBN:

     Frank couldn’t believe that his father had put Queenie back together and not told him. More secrets. More lies. The boy guessed that the coat of yellow paint was to disguise her. Queenie was a one-off. A Mini with a Union Jack painted on her would be a dead giveaway to the police.

     Category:English terms with quotations#ONEOFF

See also

• break the mold, break the mould

References

• “one-off”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.