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