The Collaborative International Dictionary of English v.0.48:

Epic \Ep"ic\, a. [L. epicus, Gr. ?, from ? a word, speech, tale,
   song; akin to L. vox voice: cf. F. ['e]pique. See Voice.]
   Narrated in a grand style; pertaining to or designating a
   kind of narrative poem, usually called an heroic poem, in
   which real or fictitious events, usually the achievements of
   some hero, are narrated in an elevated style.
   [1913 Webster]

         The epic poem treats of one great, complex action, in a
         grand style and with fullness of detail. --T. Arnold.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Epic \Ep"ic\, n.
   An epic or heroic poem. See Epic, a.
   [1913 Webster]

WordNet (r) 3.0 (2006):

epic
    adj 1: very imposing or impressive; surpassing the ordinary
           (especially in size or scale); "an epic voyage"; "of
           heroic proportions"; "heroic sculpture" [syn: epic,
           heroic, larger-than-life]
    2: constituting or having to do with or suggestive of a literary
       epic; "epic tradition" [syn: epic, epical]
    n 1: a long narrative poem telling of a hero's deeds [syn: epic
         poem, heroic poem, epic, epos]