More polite with salesman (3)
I believe the answer is:
rep
'salesman' is the definition.
(sales rep)
'more polite with' is the wordplay.
'with' says the answer is hidden in the clue.
'REP' is hidden in the letters of 'more polite'.
(Other definitions for rep that I've seen before include "agent" , "Repertory theatre" , "Theatre; fabric; salesman" , "Travelling salesman" , "what a draper usually sells" .)