A show about a nude model (7)
I believe the answer is:
cabaret
'a show' is the definition.
(cabaret is a kind of show)
'about a nude model' is the wordplay.
'about' becomes 'ca' (circa).
'a nude' becomes 'bare' (I've seen this before).
'model' becomes 't' (Ford Model T car).
'ca'+'bare'+'t'='CABARET'
(Other definitions for cabaret that I've seen before include "Film set in 1931 Berlin - floor show" , "Floor show for Arab etc" , "Liza Minnelli's entertainment?" , "Entertainment at restaurant" , "Entertainment provided in a nightclub" .)