More polite with salesman (3)
I believe the answer is:
rep
'salesman' is the definition.
(sales representative)
'more polite with' is the wordplay.
'with' says the answer is hidden in the clue.
'REP' can be found hidden inside '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" .)