Rub·ber n.
 1. One who, or that which, rubs. Specifically: (a) An instrument or thing used in rubbing, polishing, or cleaning. (b) A coarse file, or the rough part of a file. (c) A whetstone; a rubstone. (d) An eraser, usually made of caoutchouc or a synthetic rubber[4]. (e) The cushion of an electrical machine. (f) One who performs massage, especially in a Turkish bath. (g) Something that chafes or annoys; hence, something that grates on the feelings; a sarcasm; a rub.
 2. In some games, as bridge or whist, the odd game, as the third or the fifth, which decides the winner when there is a tie between the players; as, to play the rubber; also, a contest determined by the winning of two out of three games; as, to play a rubber of whist. --Beaconsfield.  “A rubber of cribbage.” --Dickens.
 3. India rubber; caoutchouc; gum elastic; -- also called natural rubber.
 5. A low-cut overshoe made of natural or synthetic rubber[4], serving to keep the feet and shoes dry when walking in the rain or on a wet surface; -- usually used in the plural.
 Antimony rubber, an elastic durable variety of vulcanized caoutchouc of a red color.  It contains antimony sulphide as an important constituent.
 Hard rubber, a kind of vulcanized caoutchouc which nearly resembles horn in texture, rigidity, etc.
 India rubber, caoutchouc. See Caoutchouc.
 Rubber cloth, cloth covered with caoutchouc for excluding water or moisture.
 Rubber dam Dentistry, a shield of thin sheet rubber clasped around a tooth to exclude saliva from the tooth.
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