Ill-will (7)
I believe the answer is:
rancour
'ill-will' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for rancour that I've seen before include "Deep-seated bitterness" , "Spiteful hostility" , "Feeling of bitterness or dislike" , "generating ill-feeling ..." , "'Bitterness, resentment (7)'" .)