De Mille film genre (4)
I believe the answer is:
'de mille film genre' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for epic that I've seen before include "Heroic; saga" , "Long adventure story" , "eg Beowulf" , "Long poem, book, film" , "Long poem telling of heroic events" .)