Impudent talk (3)
I believe the answer is:
lip
'impudent talk' is the definition.
(informal term for impolite remarks)
This is all the clue.
(Other definitions for lip that I've seen before include "Fleshy fold of mouth tissue" , "Top edge of a vessel" , "Rim of an orifice" , "Sauce" , "Edge of mouth" .)