Real Dictionary

epic
countable noun: An epic is a long book, poem, or film, whose story extends over a long period of time or tells of great events.

epic in American English
a long narrative poem in a dignified style about the deeds of a traditional or historical hero or heroes
adjective: noting or pertaining to a long poetic composition, usually centered upon a hero, in which a series of great achievements or events is narrated in elevated style
noun: an epic poem

epic in British English
adjective: denoting, relating to, or characteristic of an epic or epics
noun: a long narrative poem recounting in elevated style the deeds of a legendary hero, esp one originating in oral folk tradition