Queen once forbidden to go naked (4)
I believe the answer is:
anne
'queen once' is the definition.
'forbidden to go naked' is the wordplay.
'forbidden' becomes 'banned' (banning is a kind of forbidding).
'to go naked' indicates the central letters (I've seen 'goes naked' mean this (the outside letters are removed)).
The centre of 'banned' is 'ANNE'.
(Other definitions for anne that I've seen before include "One of the Bronte sisters" , "Last Stuart monarch, d. 1714" , "'---- of Green Gables', novel by Lucy Maud Montgomery" , "Henry's second" , "- - Hathaway, wife of Shakespeare" .)