Sit around in a hole being belligerent (7)
I believe the answer is:
hostile
'being belligerent' is the definition.
('hostile' can be similar in meaning to 'belligerent')
'sit around in a hole' is the wordplay.
'around' indicates anagramming the letters.
'in' is an insertion indicator.
'sit' anagrammed gives 'sti'.
'sti' put inside 'hole' is 'HOSTILE'.
(Other definitions for hostile that I've seen before include "malevolent" , "Aggressive" , "Bellicose" , "Antagonistic" , "Inimical" .)