Why is the ninth month called September?
"financial support (especially for medical expenses) to which one is entitled through employment or membership," 1895, plural of benefit (n.).
late 14c., "good or noble deed," also "advantage, profit," from Anglo-French benfet "well-done," from Latin benefactum "good deed," from bene facere (see benefactor). Meaning "performance or entertainment to raise money for some charitable cause" is from 1680s.
late 15c., from benefit (n.). Related: Benefited; benefiting.