Failed in audition for film (4)
I believe the answer is:
mist
'for film' is the definition.
(to film over is to mist or fog over)
'failed in audition' is the wordplay.
'failed' becomes 'missed' (missing is a kind of failing).
'in audition' indicates a 'sounds like' (homophone) clue (audition can mean hearing).
'missed' sounds like 'MIST'.
(Other definitions for mist that I've seen before include "Fine spray" , "Think fog or low cloud" , "Slight fog" , "Haze" , "Watery vapour" .)