[ 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.

Nearby words

  1. unlearn,
  2. unlearned,
  3. unlearnt,
  4. unleash,
  5. unleavened,
  6. unlessoned,
  7. unlettered,
  8. unlevel,
  9. unlicensed,
  10. unlicked

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. 2019

Examples 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

Word Origin and History for unless



mid-15c., earlier onlesse, from on lesse (than) "on a less condition (than)," the first syllable originally on, but the negative connotation and the lack of stress changed it to un-.

Online Etymology Dictionary, © 2010 Douglas Harper