unless
/ɪnˈlɛs/ conjunction
Forms unlesse unlessen
- conjunction Except on a specified condition; if not. “I’m leaving unless I get a pay rise.”
- conjunction If not; used with counterfactual conditionals.
- conjunction Except if; used with hypothetical conditionals.
Antonyms
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-.
Webster’s 1913
- conjunction Upon any less condition than (the fact or thing stated in the sentence or clause which follows); if not; supposing that not; if it be not; were it not that; except; as, we shall fail unless we are industrious.
Etymology [Formerly, onles, onlesse, onlesse that, that is, in less, in a less case. See On, and Less.]
Sources: Wiktionary · Webster’s 1913 — from the Wiktionary entry “unless”, CC BY-SA 4.0. Details