What about opening with film title? (7)
I believe the answer is:
epithet
'title?' is the definition.
(I've seen this before)
'what about opening with film' is the wordplay.
I cannot really understand how this works, but
'opening' could be 'pit' (opening in the ground) and 'pit' is located in the answer.
'what' could be 'eh' (sound used to ask 'what?' or 'pardon?') and 'eh' is located in the leftover letters.
'film' could be 'et' (E.T. the Extra-Terrestrial) and 'et' is found 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 epithet that I've seen before include "Descriptive work or phrase" , "nickname" , "Descriptive term used to express a real quality" , "What characterises" , "qualifier" .)