Punning

from WordNet (r) 3.0 (2006)

punning
    n 1: a humorous play on words; "I do it for the pun of it"; "his
         constant punning irritated her" [syn: {pun}, {punning},
         {wordplay}, {paronomasia}]

from The Collaborative International Dictionary of English v.0.48

Pun \Pun\, v. i. [imp. & p. p. {Punned}; p. pr. & vb. n.
   {Punning}.]
   To make puns, or a pun; to use a word in a double sense,
   especially when the contrast of ideas is ludicrous; to play
   upon words; to quibble. --Dryden.
   [1913 Webster]