Why is the ninth month called September?
early 14c. (late 12c. as a surname), joynour "maker of furniture, small boxes, etc.," from Old French joigneor "joiner, carpenter," agent noun from joindre "to join" (see join). A craftsman who did lighter and more ornamental work than a carpenter. Meaning "one who makes a habit of joining" (societies, clubs, etc.) is from 1890. Related: Joinery.