early 15c., "incapacity;" mid-15c., "any harm or injury," from Old French détriment or directly from Latin detrimentum "a rubbing off; a loss, damage, defeat," from past-participle stem of detere "to wear away," figuratively "to weaken, impair," from de "away" (see de-) + terere "to rub, wear" (from PIE root *tere- (1) "to rub, turn"). Meaning "that which causes harm or injury" is from c. 1500.
