IPA: /ɛˈpoʊpi/
KK: /ɛˈpoʊpi/
A long and grand poem that tells a story, often about heroic deeds and events of great significance.
Homer's 'Iliad' is one of the most famous epopees in Western literature.
Epopee is derived from the French word 'épopée', which comes from the Latin 'epopeia', meaning a narrative poem or epic. The term itself is rooted in the Greek 'epopoiia' (from 'epos', meaning word or song, and 'poiein', meaning to make). Thus, it refers to a grand narrative or story told in poetic form.
Think of 'epic' stories being 'made' ('poiein') with 'words' ('epos') — that's why an 'epopee' is a grand narrative.