Animosity from soldier in hearing (7)
I believe the answer is:
rancour
'animosity' is the definition.
(I've seen this before)
'soldier in hearing' is the wordplay.
'soldier' becomes 'ranker' (ranker is a kind of soldier).
'in hearing' indicates a 'sounds like' (homophone) clue.
'ranker' sounds like 'RANCOUR'.
'from' is the link.
(Other definitions for rancour that I've seen before include "Spiteful hostility" , "Bitter feeling or ill-will" , "Bitterness or resentfulness" , "Feeling of bitterness or dislike" , "Hard feelings" .)