Actor in drag ate nuts (9)
I believe the answer is:
tragedian
'actor' is the definition.
(I know that tragedian is a type of actor)
'in drag ate nuts' is the wordplay.
'nuts' indicates an anagram (nuts can mean crazy).
'in'+'drag'+'ate'='indragate'
'indragate' is an anagram of 'TRAGEDIAN'.
(Other definitions for tragedian that I've seen before include "A great din (anag) - actor" , "Serious actor" , "Dramatist" , "Egad, I rant about actor in sad drama" , "Egad, I rant about dramatic actor" .)