Indy setter shortened piece of wordplay (3)
I believe the answer is:
pun
'piece of wordplay' is the definition.
(punning is a type of wordplay)
'indy setter shortened' is the wordplay.
'indy setter' becomes 'Punk' (Punk is a crossword setter for the Independent).
'shortened' means to remove the last letter.
'punk' with its final letter taken off is 'PUN'.
(Other definitions for pun that I've seen before include "A play on words, perhaps the lowest form of wit" , "Bit of paronomasia; witticism" , "A play on words - not the height of wit" , "Form of wordplay" , "conceit by a wordsmith?" .)