Why is the ninth month called September?
early 15c., "income from property or possessions," from Middle French revenue, in Old French, "a return," noun use of fem. past participle of revenir "come back" (10c.), from Latin revenire "return, come back," from re- "back" (see re-) + venire "come" (see venue). Meaning "public income" is first recorded 1680s; revenue sharing popularized from 1971. Revenuer "U.S. Department of Revenue agent," the bane of Appalachian moonshiners, first attested 1880.
The income of local, state, or national governments.