a) A traditional story which embodies a belief regarding some fact or phenomenon of experience, and in which often the forces of nature and of the soul are personified; a sacred narrative regarding a god, a hero, the origin of the world or of a people, etc.
Myth was the product of mans emotion and imagination, acted upon by his surroundings. (E. Clodd, Myths & Dreams (1885), 7, cited after OED)
b) such stories as a genre
Father Flanagan was legendary, his institution an American myth. (Tucson (Arizona) Citizen, 20 September 1979, 5A/3, cited after OED)
See Also: mythic, mythical, mythicize, mythologem, mythological, mythology, mythopoeia, mythopoeic, mythopoesis, mythos, pseudomyth
Wikipedia foundation.