unless

[uhn-les, uhn-]

conjunction

1. except under the circumstances that.

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

preposition

1. except; but; save.

   Nothing will come of it, unless disaster.

unless

/ ʌnˈlɛs /

conjunction

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

   they'll sell it unless he hears otherwise

preposition

1. rare,  except

Word History and Origins

Origin of unless¹

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

Word History and Origins

Origin of unless¹

C14: onlesse , from on _on + lesse _less ; compare French à moins que, literally: at less than

Example Sentences

You probably haven’t changed your web browser in a decade, because there was no reason to switch unless you had to.

Read more on The Wall Street Journal

Friday’s delayed consumer price inflation report is likely to be a key hurdle for markets heading into next week, but unless it indicates a big tick higher as a result of tariff-related price pressures, Bowersock Hill thinks it’s unlikely to weigh heavily on next week’s Fed rate decision.

Read more on Barron's

Unless you’re a daredevil who loves to incur risk, most of the time you should bet against beta.

Read more on MarketWatch

Lionel Messi has been the standout MLS player so far, but the season will be regarded as a failure unless he brings home play-off success to Miami.

Read more on BBC

Unless your destination is Mayan Warrior, that is.

Read more on Los Angeles Times