noun

1. a traditional story of unknown authorship, ostensibly with a historical basis, but serving usually to explain some phenomenon of nature, the origin of man, or the customs, institutions, religious rites, etc. of a people: myths usually involve the exploits of gods and heroes
2. such stories collectively; mythology
3. any fictitious story, or unscientific account, theory, belief, etc.
4. any imaginary person or thing spoken of as though existing

Etymology: LL mythos < Gr, a word, speech, story, legend