Large-scale (4)
I believe the answer is:
epic
'large-scale' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for epic that I've seen before include "Long, heroic story" , "eg The Iliad" , "Tale of heroic deeds" , "long poem telling of heroic deeds" , "On a grand scale like long poem" .)