Thug, roughneck (7)
I believe the answer is:
ruffian
This clue is a double definition.
'thug' is the first definition.
(I've seen this before)
'roughneck' is the second definition.
(I know that roughneck can be written as ruffian)
(Other definitions for ruffian that I've seen before include "Funfair (anag)" , "Thug" , "Violent, lawless person" , "Hoodlum" , "Roughneck" .)