Sulk where poem rewritten (4)
I believe the answer is:
mope
'sulk' is the definition.
(I've seen this in another clue)
'poem rewritten' is the wordplay.
'rewritten' is an anagram indicator.
'poem' anagrammed gives 'MOPE'.
'where' is the link.
(Other definitions for mope that I've seen before include "listless person" , "Be listless and apathetic" , "Be mildly depressed" , "Hang around being miserable" , "Move listlessly and aimlessly" .)