Amaze Tory leader with a noise outside (7)
I believe the answer is:
astound
'amaze' is the definition.
(synonyms)
'tory leader with a noise outside' is the wordplay.
'leader' says to take the initial letters.
'with' means one lot of letters go next to another.
'noise' becomes 'sound' (I've seen this before).
'outside' means one lot of letters goes inside another (some letters go outside others).
The first letter of 'tory' is 't'.
'a' next to 'sound' is 'asound'.
't' inserted into 'asound' is 'ASTOUND'.
(Other definitions for astound that I've seen before include "Bowl over" , "Bewilder" , "Fill with wonder or astonishment" , "Amaze, astonish" , "Stagger" .)