lest
conjunction
ˈlest 
: for fear that —often used after an expression denoting fear or apprehension
worried lest she should be latehesitant to speak out lest he be fired
Word History
Etymology
Middle English les the, leste, from Old English thȳ lǣs the, from thȳ (instrumental of thæt that) + lǣs + the, relative particle
First Known Use
before the 12th century, in the meaning defined above
Kids Definition
lest
conjunction
ˈlest
: for fear that
"I have to be sharp and clever, lest I go hungry."
E. B. White, Charlotte's Web
E. B. White, Charlotte's Web