Naked Tiller girl is banned (7)
I believe the answer is:
illegal
'is banned' is the definition.
(similar in meaning)
'naked tiller girl' is the wordplay.
'naked' says to take the centre.
'girl' becomes 'gal' (synonyms).
The middle letters of 'tiller' are 'ille'.
'ille'+'gal'='ILLEGAL'
(Other definitions for illegal that I've seen before include "crooked" , "Not in conformity with law" , "Ignoring certain acts" , "Wrong" , "Prohibited by law" .)