Film's about finished (5)
I believe the answer is:
cover
'film's' is the definition.
(thesaurus)
'about finished' is the wordplay.
'about' becomes 'c' (abbreviation for 'circa').
'finished' becomes 'over' ('over' can be similar in meaning to 'finished').
'c'+'over'='COVER'
(Other definitions for cover that I've seen before include "Enshroud" , "Conceal a thing or fact - . . . . . up" , "Mask, hide" , "Blanket" , "Deal with" .)