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; see on, less

Example Sentences

They’re the ones to beat, unless Sally Field’s sentimental heroine in ‘Remarkably Bright Creatures’ warms voters’ hearts.”

From Los Angeles Times • May 19, 2026

Another concerns so-called "sunrise" and "sunset" clauses under which the EU side of the accord would kick in once the United States makes fully good on its pledges, and would expire unless renewed in 2028.

From Barron's • May 19, 2026

The "long term scope for further revenue increases is becoming limited unless fundamental tax reforms are envisaged", it said.

From BBC • May 18, 2026

Today a large share of monthly spending disappears into medical premiums, deductibles and copayments that produce nothing visible unless catastrophe strikes.

From The Wall Street Journal • May 18, 2026

Vinny could not believe that Deutsche Bank would let this guy loose to run around and torpedo their market unless it served the narrow interests of Deutsche Bank.

From "The Big Short" by Michael Lewis