Know why cattywampus was trending last week?
early 15c., "exposition of myths," from Middle French mythologie and directly from Late Latin mythologia, from Greek mythologia "legendary lore, a telling of mythic legends; a legend, story, tale," from mythos "myth" (of unknown origin) + -logy "study." Meaning "a body of myths" first recorded 1781.
The body of myths belonging to a culture. Myths are traditional stories about gods and heroes. They often account for the basic aspects of existence — explaining, for instance, how the Earth was created, why people have to die, or why the year is divided into seasons. Classical mythology — the myths of the ancient Greeks and Romans — has had an enormous influence on European and American culture.