Hostile part of song (6)
I believe the answer is:
averse
This clue is a double definition.
'hostile' is the first definition.
(I've seen this before)
'part of song' is the second definition.
(a single verse)
(Other definitions for averse that I've seen before include "Strongly opposed (to something)" , "Unwilling or disinclined, perhaps to hard work" , "Having a strong opposition (to)" , "Metal rod; card game" , "Indisposed" .)