myth from (mythos) identifies a sacred story or narrative containing supernatural, divine or heroic beings, arranged in a coherent system, passed down orally, and linked to the spiritual or religious life of a community. Myths have existed in all cultures since before recorded history. Myths are often set in mythical time, a time before time or history begins, and are intended to explain the universal and local beginnings ("creation myths" and "founding myths"), natural phenomena, inexplicable cultural conventions, and anything else for which no simple explanation presents itself. In this sense myth is distinct from fiction, legend, fairy tale, folklore, fable and tale. A myth may also describe in story form, how elements of the human psyche interact (eg She: Understanding Feminine Psychology, Robert A Johnson, ISBN 0-06-096397-2).
myth a comparatively recent term that has been applied to stories that purport to have a basis in fact, but when examined are fictional. For example; urban myth, the myth of El Dorado. This usage, which is often pejorative, may have arisen from labelling the religious stories and beliefs of other cultures as being incorrect. As a term it allows no distinction between fiction, legend, fairy tale, folklore, fable, and urban legend, each of which has a precise meaning.
Mythology refers either to the act of relating myths or to the branch of knowledge dealing with the collection, study and interpretation of myths together with mythography, and folkloristics. As a field of study mythology is most closely associated with anthropology, psychology, literary and classical studies, political science and sociology, the later having the distinction of not requiring that a story be 'sacred' to qualify as a myth.
mythic is used to refer to a quality that partakes of myth, it is often used to describe elements of narratives that aren't necessarily myths. for example; superhuman strength, the ability to fly etc. Mythic can also be used as a pejorative to doubt the factual accuracy of an account.
mythical is a term that loosely denotes an element taken from a myth, legend or fable. for example; a frog prince, golden fleeces, elves, unicorns. It is sometimes also used to refer to subjects that cannot be verified empirically i.e. I'm still expecting my mythical pay rise.