Ill-mannered one (4)
I believe the answer is:
lout
'ill-mannered one' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lout that I've seen before include "Awkward and stupid person" , "disrespectful person" , "Ill-mannered person" , "A coarse ignorant fellow" , "Ill-mannered or aggressive man" .)