Ridiculed when free to enter action (7)
I believe the answer is:
derided
'ridiculed' is the definition.
(I've seen this before)
'free to enter action' is the wordplay.
'free' becomes 'rid' ('rid' can be a synonym of 'free').
'to enter' indicates putting letters inside.
'action' becomes 'deed' (deed is a kind of action).
'rid' inserted within 'deed' is 'DERIDED'.
'when' acts as a link.
(Other definitions for derided that I've seen before include "Ridiculed" , "Treated or spoke of with contempt" , "Mocked, laughed at" , "Did rubbish" , "Scorned" .)