Nightclub entertainment (9)
'nightclub entertainment' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for cabaret that I've seen before include "Evening entertainment as in nightclub" , "Bear cat (anag.)" , "Series of acts" , "Film set in 1931 Berlin - floor show" , "Musical - nightclub entertainment" .)
(Another definition for floorshow that I've seen is " What goes on in a nightclub".)