full definition of myth 1 a a usually traditional story of ostensibly historical events that serves to unfold part of the world view of a people or explain a practice belief or natural phenomenon b parable allegory 2b an unfounded or false notion3ull definition of myth 1 a a usually traditional story of ostensibly historical events that serves to unfold part of the world view of a people or explain a practice belief or natural phenomenon b parable allegory 2 b an unfounded or false notion 3