unless

American  

[uhn-les, uhn-] / ʌnˈlɛs, ən- /

conjunction

1. except under the circumstances that.

   I'll be there at nine, unless the train is late.

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preposition

1. except; but; save.

   Nothing will come of it, unless disaster.

unless British  

/ ʌnˈlɛs /

conjunction

1. (subordinating) except under the circumstances that; except on the condition that

   they'll sell it unless he hears otherwise

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preposition

1. rare except

Etymology

Origin of unless

1400–50; late ME prepositional phrase on less (also o less(e) , earlier upon less ) on a lesser footing or condition (than); first used as a preposition and conjunction in the early 16th century; on, less

Example Sentences

With Plum and likely Atkins in the fold, the Sparks could now use an upgraded ball-handler, unless they go with Plum at the point guard spot and focus on bringing in another forward.

From Los Angeles Times • Apr. 10, 2026

"This damage is going to continue unless it ceases or it's stopped by An Garda Síochána and the defence forces," he added.

From BBC • Apr. 9, 2026

"This whole thing is a package. We can't explore deeper unless we are doing a few things that are inconvenient, unless we're making a few sacrifices, unless we're taking a few risks," she said.

From Barron's • Apr. 9, 2026

This goes for the putting greens, too, unless you are playing a match.

From The Wall Street Journal • Apr. 9, 2026

“Pixies don’t bug you unless you’re near gold. They definitely don’t bite unless you have gold. Lots of it.”

From "Rump: The (Fairly) True Story of Rumpelstilskin" by Liesl Shurtliff