Copy of paper (3)
I believe the answer is:
ape
'copy' is the definition.
(ape can mean to copy or imitate)
'of paper' is the wordplay.
'of' indicates the answer is hidden within the clue.
'APE' is hidden within 'paper'.
(Other definitions for ape that I've seen before include "Wild animal" , "gorilla" , "Idiot" , "Take off" , "Mimic the primate" .)