[ uhn-les, uh n- ]
/ ʌnˈlɛs, ən- /


except under the circumstances that: I'll be there at nine, unless the train is late.


except; but; save: Nothing will come of it, unless disaster.


Discover The Influence Of Portuguese On English Via This Quiz!
We’ve gathered some interesting words donated to English from Portuguese … as well as some that just don’t translate at all. Do you know what they mean?
Question 1 of 11
Which of the following bird names traces its immediate origin to Portuguese?

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
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for unless

British Dictionary definitions for unless

/ (ʌnˈlɛs) /


(subordinating) except under the circumstances that; except on the condition thatthey'll sell it unless he hears otherwise


rare except

Word Origin for unless

C14: onlesse, from on on + lesse less; compare French à moins que, literally: at less than
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012