Film us leaving cat food endlessly (6)
I believe the answer is:
psycho
'film' is the definition.
(Alfred Hitchcock film)
'us leaving cat food endlessly' is the wordplay.
'leaving' suggests deleting specific letters.
'cat' becomes 'pussy' (pussy can mean a cat).
'food endlessly' becomes 'cho' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'pussy' with 'us' taken away is 'psy'.
'psy'+'cho'='PSYCHO'
Can you help me to learn more?
(Other definitions for psycho that I've seen before include "Well-known Hitchcock film" , "Hitchcock's 1960 classic chiller" , "In brief, person with severe mental disorder - ask Alfred Hitchcock" , "1960 Hitchcock film" , "Hitchcock's 1960 thriller" .)