He hates fighting in cover (7)
I believe the answer is:
sheathe
'cover' is the definition.
(to sheathe something is to cover it)
'he hates fighting in' is the wordplay.
'fighting' indicates anagramming the letters (I've seen this in other clues).
'in' means one lot of letters goes inside another.
'hates' anagrammed gives 'sathe'.
'he' put within 'sathe' is 'SHEATHE'.
(Other definitions for sheathe that I've seen before include "Encase in protection" , "Put (a sword) it its cover" , "Put (a sword) into case" , "Put away (a sword)" , "Put into scabbard" .)