Source : Webster's Revised Unabridged Dictionary (1913)

Gong \Gong\, n. [AS. gong, gang, a going, passage, drain. See
   {Gang}.]
   A privy or jakes. [Obs.] --Chaucer.

   {Gong farmer}, {Gong man}, a cleaner of privies. [Obs.]

Gong \Gong\, n.
   1. [Malayan (Jav.) g[=o]ng.] An instrument, first used in the
      East, made of an alloy of copper and tin, shaped like a
      disk with upturned rim, and producing, when struck, a
      harsh and resounding noise.

            O'er distant deserts sounds the Tartar gong.
                                                  --Longfellow.

   2. (Mach.) A flat saucerlike bell, rung by striking it with a
      small hammer which is connected with it by various
      mechanical devices; a stationary bell, used to sound calls
      or alarms; -- called also {gong bell}.

   {Gong metal}, an alloy (78 parts of copper, 22 of tin), from
      which Oriental gongs are made.

Source : WordNet®

gong
     n 1: a percussion instrument consisting of a metal plate that is
          struck with a soft-headed drumstick [syn: {tam-tam}]
     2: a percussion instrument consisting of vertical metal tubes
        of different lengths that are struck with a hammer [syn: {chime},
         {bell}]

gong
     v : sound a gong