Part of poetic line appearing ahead of time in film part (7)
I believe the answer is:
footage
'part' is the definition.
(I have seen 'Part of film' mean 'footage' so perhaps 'part' could also mean 'footage')
'part of poetic line appearing ahead of time in film' is the wordplay.
I cannot really understand how this works, but
'part' could be 'foot' (foot is a kind of part) and 'foot' is found in the answer.
'time' could be 'age' (an age is a period of time) and 'age' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for footage that I've seen before include "Quantity of film (of event)" , "Piece of filmed material" , "Part of film" , "Length of film" , "Film that has been shot" .)