The ouroboros or uroboros (/ˌjʊərəˈbɒrəs/) is an ancient symbol depicting a serpent or dragon eating its own tail. The ouroboros entered Western tradition via ancient Egyptian iconography and the Greek magical tradition. It was adopted as a symbol in Gnosticism and Hermeticism and most notably in alchemy. The term derives from Ancient Greek οὐροβόρος, from οὐρo oura 'tail' plus -βορός -boros '-eating'. The ouroboros is often interpreted as a symbol for eternal cyclic renewal or a cycle of life, death, and rebirth; the snake’s skin-sloughing symbolizes the transmigration of souls. The snake biting its own tail is a fertility symbol in some religions: the tail is a phallic symbol and the mouth is a yonic or womb-like symbol.