Ambassador takes on right wing idea (6)
I believe the answer is:
theory
'wing idea' is the definition.
'theory' can be an answer for 'idea' (theory is a kind of idea). I am not certain of the 'wing' bit.
'ambassador takes on right' is the wordplay.
'ambassador' becomes 'HE' (His or Her Excellency).
'takes on' indicates putting letters inside (inserted letters are worn or taken on).
'right' becomes 'tory' (Tory can mean Conservative or right-wing).
'he' going inside 'tory' is 'THEORY'.
Can you help me to learn more?
(Other definitions for theory that I've seen before include "Supposition, set of ideas" , "Opinion or supposition to explain something" , "Suggested explanation" , "Conjecture, hypothesis" , "Explanation or system of anything" .)