Main Entry: lest

Pronunciation: \ˈlest\

Function: conjunction

Etymology: Middle English les the, leste, from Old English thȳ lǣs the, from thȳ (instrumental of thæt that) + lǣs + the, relative particle

Date: before 12th century

: for fear that —often used after an expression denoting fear or apprehension <worried lest she should be late> <hesitant to speak out lest he be fired>