Lacking civility (4)
I believe the answer is:
rude
'lacking civility' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for rude that I've seen before include "Blue" , "Primitive; impolite" , "Ill-mannered; hearty" , "Impolite - simple" , "Impolite; basic" .)