Brief film entertaining wife (6)
I believe the answer is:
lawyer
'brief' is the definition.
(slang term for a lawyer)
'film entertaining wife' is the wordplay.
'film' becomes 'layer' (film can mean a thin layer of something).
'entertaining' indicates putting letters inside (inviting in, as for dinner).
'wife' becomes 'w' (abbreviation).
'layer' going around 'w' is 'LAWYER'.
(Other definitions for lawyer that I've seen before include "Solicitor, for example" , "Man at the bar?" , "brief" , "Legal adviser" , "Legal eagle" .)