Why is the ninth month called September?
1530s, "fumes from a burning substance," from Middle French parfum (16c.), from parfumer "to scent," from Old Provençal perfumar or cognate words in dialectal Italian (perfumare) or Spanish (perfumar), from Latin per- "through" (see per) + fumare "to smoke" (see fume (n.)). Meaning "fluid containing agreeable essences of flowers, etc.," is attested from 1540s.
1530s, "to fill with smoke or vapor," from perfume (n.) or from Middle French parfumer. Meaning "to impart a sweet scent to" is from 1530s. Related: Perfumed; perfuming.