one-timeˈone-time (also one-off British EnglishBrE) adjectiveadj [only before a noun] a one-time event, payment etc happens once and is not part of a regular series of such eventsLawyers face a one-off tax hit as a result of the tax changes.
The company expects to take a one-time charge of $10.3 million (=show it in its accounts) due primarily to restructuring.