Bloke's not entirely likeable group's breaking camp (10)
I believe the answer is:
histrionic
'camp' is the definition.
(both can mean theatrical or affected)
'bloke's not entirely likeable group's breaking' is the wordplay.
'bloke's' becomes 'his'.
'not entirely' means to remove the last letter.
'likeable' becomes 'nice'.
'group' becomes 'trio' (a group of three**).
'breaking' means one lot of letters goes inside another.
'nice' with its last letter taken off is 'nic'.
'his'+'nic'='hisnic'
'hisnic' going around 'trio' is 'HISTRIONIC'.
(Other definitions for histrionic that I've seen before include "Overly theatrical" , "Of acting; dramatic" , "Melodramatic" .)