rubber (Adjective) — (banking) returned for lack of funds. ex. "a rubber check"
rubber (Noun) — An elastic material obtained from the latex sap of trees (especially trees of the genera Hevea and Ficus) that can be vulcanized and finished into a variety of products.
rubber (Noun) — Any of various synthetic elastic materials whose properties resemble natural rubber.
rubber (Noun) — An eraser made of rubber (or of a synthetic material with properties similar to rubber); commonly mounted at one end of a pencil.
rubber (Noun) — Contraceptive device consisting of a sheath of thin rubber or latex that is worn over the penis during intercourse.
rubber (Noun) — A waterproof overshoe that protects shoes from water or snow.
rubber (Noun) — A tire consisting of a rubber ring around the rim of an automobile wheel.
rubber (Noun) — A series of an odd number of games or matches of which a majority must be won.
rubber (Verb) — Coat or impregnate with rubber. ex. "rubber fabric for rain coats"