Express disapproval over socialist being disciplined (7)
I believe the answer is:
tutored
'being disciplined' is the definition.
(I've seen this before)
'express disapproval over socialist' is the wordplay.
'express disapproval' becomes 'tut' (tutting is making a disapproving sound).
'over' becomes 'o' (cricket abbreviation).
'socialist' becomes 'red' (socialism is often associated with the colour red).
'tut'+'o'+'red'='TUTORED'
(Other definitions for tutored that I've seen before include "Trained" , "Was coach" , "Disciplined" , "Coached" , "Rude tot (anag.)" .)