MYTH
Main Entry: myth
Pronunciation: \ˈmith\
Function: noun
Etymology: Greek mythos
Date: 1830
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 a : a popular belief or tradition that has grown up around something or someone; especially : one embodying the ideals and institutions of a society or segment of society
b : an unfounded or false notion
3 : a person or thing having only an imaginary or unverifiable existence

4 : the whole body of myths

http://www.merriam-webster.com/dictionary/myth