The Collaborative International Dictionary of English v.0.48:

Bung \Bung\, v. t. [imp. & p. p. Bunged; p. pr. & vb. n.
   Bunging.]
   To stop, as the orifice in the bilge of a cask, with a bung;
   to close; -- with up.
   [1913 Webster]

   To bung up, to use up, as by bruising or over exertion; to
      exhaust or incapacitate for action. [Low]
      [1913 Webster]

            He had bunged up his mouth that he should not have
            spoken these three years.             --Shelton
                                                  (Trans. Don
                                                  Quixote).
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bung \Bung\ (b[u^]ng), n. [Cf. W. bwng orfice, bunghole, Ir.
   buinne tap, spout, OGael. buine.]
   1. The large stopper of the orifice in the bilge of a cask.
      [1913 Webster]

   2. The orifice in the bilge of a cask through which it is
      filled; bunghole.
      [1913 Webster]

   3. A sharper or pickpocket. [Obs. & Low]
      [1913 Webster]

            You filthy bung, away.                --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

bung
    n 1: a plug used to close a hole in a barrel or flask [syn:
         bung, spile]
    v 1: give a tip or gratuity to in return for a service, beyond
         the compensation agreed on; "Remember to tip the waiter";
         "fee the steward" [syn: tip, fee, bung]
    2: close with a cork or stopper