Object about terrible pun as a contribution (5)
I believe the answer is:
input
'a contribution' is the definition.
(input means someone's contribution to something)
'object about terrible pun' is the wordplay.
'object' becomes 'it' (pronoun for an inanimate object).
'about' indicates putting letters inside.
'terrible' indicates an anagram.
'pun' is an anagram of 'npu'.
'it' placed around 'npu' is 'INPUT'.
'as' is the link.
(Other definitions for input that I've seen before include "Signal feeding a circuit" , "supply" , "Signal entering a circuit" , "store" , "Feed data into a computer" .)