Piece of wordplay (3)
I believe the answer is:
pun
'piece of wordplay' is the definition.
(punning is a type of wordplay)
This is all the clue.
(Other definitions for pun that I've seen before include "Humorous play on words" , "A play on words - not the height of wit" , "Double entendre" , "A play on words, not really wit" , "Form of wordplay" .)