Definitions of rubber:

• noun:   latex from trees (especially trees of the genera Hevea and Ficus)
• noun:   contraceptive device consisting of a thin rubber or latex sheath worn over the penis during intercourse
• noun:   an eraser made of rubber (or of a synthetic material with properties similar to rubber); commonly mounted at one end of a pencil
• noun:   a waterproof overshoe that protects shoes from water or snow
• verb:   coat or impregnate with rubber

  Example: "Rubberize fabric for rain coats"

• adjective:   made of rubber and therefore water-repellent

  Example: "Rubber boots"

• adjective:   returned for lack of funds

  Example: "A rubber check"