Thor"ough*pin` (?), n. (Far.) A disease of the hock (sometimes of the knee) of a horse, caused by inflammation of the synovial membrane and a consequent excessive secretion of the synovial fluid; -- probably so called because there is usually an oval swelling on each side of the leg, appearing somewhat as if a pin had been thrust through.

Thor"ough*pin` (?), n. (Far.) A disease of the hock (sometimes of the knee) of a horse, caused by inflammation of the synovial membrane and a consequent excessive secretion of the synovial fluid; -- probably so called because there is usually an oval swelling on each side of the leg, appearing somewhat as if a pin had been thrust through.