Some cop, corrupt, is set up (7)
I believe the answer is:
compose
'is set up' is the definition.
(thesaurus)
'some cop corrupt' is the wordplay.
'corrupt' indicates an anagram.
'some'+'cop'='somecop'
'somecop' is an anagram of 'COMPOSE'.
(Other definitions for compose that I've seen before include "Create or put together" , "Make up, create" , "18 [GET READY]" , "Write a piece of music" , "Devise" .)