Why is the ninth month called September?
late 14c., contraction of remenant (c.1300), from Old French remanant "rest, remainder, surplus," noun use of present participle of remanoir "to remain" (see remain (v.)). Specific sense of "end of a piece of drapery, cloth, etc." is recorded from early 15c. An Old English word for "remnant" was endlaf.