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

“That means legislation in the Senate could be subject to a filibuster, unless it is part of a budget reconciliation bill or the Republicans eliminate the filibuster,” Kantrowitz said.

From Salon

That ensures more deadly and destructive heat waves, storms, floods and droughts unless we do more, fast, to drive down emissions.

From Los Angeles Times

If the demand does not comply with either of these requirements, the leaseholder has a legal right not to pay unless and until the service charge is demanded in the proper manner.

From BBC

"The risk of flooding, compounded by sinking land and beach loss, could displace millions and damage critical infrastructure unless robust adaptation strategies are implemented," said Shirzaei.

From Science Daily

Unless maybe the theater is screening "The Rocky Horror Picture Show" or something.

From Salon