Drawing a politician out (3)
I believe the answer is:
map
'drawing' is the definition.
(thesaurus)
'a politician out' is the wordplay.
'politician' becomes 'mp' (Member of Parliament).
'out' means one lot of letters goes inside another.
'a' going within 'mp' is 'MAP'.
(Other definitions for map that I've seen before include "Chart" , "Travel guide" , "Sketch" , "(Make a) geographical representation" , "face" .)