Princess, aficionado in anti-movement (7)
I believe the answer is:
infanta
'princess' is the definition.
(thesaurus)
'aficionado in anti-movement' is the wordplay.
'aficionado' becomes 'fan' (I've seen this before).
'in' indicates putting letters inside.
'movement' indicates an anagram.
'anti' is an anagram of 'inta'.
'fan' put within 'inta' is 'INFANTA'.
(Other definitions for infanta that I've seen before include "Formerly, the daughter of a Spanish king" , "noble abroad" , "Historically, a daughter of the Spanish king - sounds very young" , "girl in foreign court" , "Daughter of a Spanish or Portuguese king" .)