An incubus (plural incubi), according to a number of mythological and legendary traditions, is a demon in male form supposed to lie upon sleepers, especially women, in order to have sexual intercourse with them. Religious tradition holds that repeated intercourse with an incubus or succubus may result in the deterioration of health, or even death. Its female counterpart is the succubus. The word is derived from the Latin preposition in, which in this case means on top of, and cubo, which is Latin for "I lie". The word incubo translates into "I lie on top".