unless

Definition

Except on a specified condition; if not.

Etymology

From Middle English unlesse, earlier on lesse (modern on + less), from (not) on lesse (than) (“(not) on a less compelling condition (than)”). The quality of negation in the word and the lack of stress changed on to un-.

Example Sentences

• "I’m leaving unless I get a pay rise."
• "You can't go out unless it stops raining."
• "Unless part of the staff, you are not allowed beyond this point."