Extremely unpleasant being mutinous? (9)
I believe the answer is:
revolting
I believe this is a double definition.
'extremely unpleasant' is the first definition.
'being mutinous?' is the second definition.
(Other definitions for revolting that I've seen before include "Rising in rebellion" , "rioting" , "Repulsive" , "Loathsome" , "Disgusting" .)