Copy of the paper (3)
I believe the answer is:
ape
'copy' is the definition.
('ape' can be a synonym of 'copy')
'of the paper' is the wordplay.
'of' indicates a hidden word.
'APE' is hidden in the letters of 'the paper'.
(Other definitions for ape that I've seen before include "Parrot" , "Our cousin" , "Mimic the primate" , "Copy - primate" , "intelligent creature" .)