Film actor quietly leaving (5)
I believe the answer is:
layer
'film' is the definition.
(film can mean a thin layer of something)
'actor quietly leaving' is the wordplay.
'actor' becomes 'player' (synonyms).
'quietly' becomes 'p' (p for piano and quiet).
'leaving' suggests deleting specific letters.
'player' with 'p' taken out is 'LAYER'.
(Other definitions for layer that I've seen before include "Thickness of material or earth - relay it" , "Film" , "Tier or thickness - or a hen?" , "plate?" , "course" .)