Attack featured where film is being made (5)
I believe the answer is:
onset
'attack' is the definition.
(archaic term for a military attack)
'featured where film is being made' is the wordplay.
I cannot really see how this works, but
'film' could be 'et' (E.T. the Extra-Terrestrial) and 'et' is present in the answer.
The remaining letters 'ons' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for onset that I've seen before include "Appearance of" , "starting?" , "Inception" , "Assault; beginning" , "First signs" .)