late 14c., benefet, "good or noble deed; helpful or friendly action," also "a beneficial thing; advantage, profit," from Anglo-French benfet (Old French bienfait), from Latin benefactum "good deed," from bene facere, from bene "well" (see bene-) + facere "to do" (from PIE root *dhe- "to set, put"). Meaning "public performance or entertainment to raise money for some deserving unfortunate person or charitable cause" is from 1680s.
