Bar part of film maybe right away (6)
I believe the answer is:
except
'bar' is the definition.
(both can mean 'not including')
'part of film maybe right away' is the wordplay.
I cannot really understand how this works, but
'part' could be 'pt' (abbreviation) and 'pt' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for except that I've seen before include "Not including - bar" , "Not including or leave out" , "Not including, omit this" , "Leaving out" , "Exclude, take out" .)