Ruin Gents, trashed, being revolting (9)
I believe the answer is:
insurgent
'being revolting' is the definition.
(I've seen this before)
'ruin gents trashed' is the wordplay.
'trashed' is an anagram indicator.
'ruin'+'gents'='ruingents'
'ruingents' anagrammed gives 'INSURGENT'.
(Other definitions for insurgent that I've seen before include "Revolting" , "Rebel, revolutionary" , "rising" , "Unresting like a rebel" , "freedom fighter" .)