lever (n.)

"simple machine consisting of a rigid piece acted upon at different points by two forces," c. 1300, from Old French levier (12c.) "a lifter, a lever, crowbar," agent noun from lever "to raise" (10c.), from Latin levare "to raise," from levis "light" in weight, "not heavy," also, of motion, "quick, rapid, nimble;" of food, "easy to digest;" figuratively "slight, trifling, unimportant; fickle, inconsistent;" of punishments, etc., "not severe," from PIE root *legwh- "not heavy, having little weight." As a verb, 1856, from the noun.