LUCIFER1, LUCYFER, is the name of the morning star. Cicero says that Lucifer is the Latin translation of Greek phosphorus, a name for Venus (De natura deorum II.20, 53). Ovid refers to Venus as Lucifer (Heroides XVIII.112).
Hesperus rises as the evening star but pales when the sun rises and is then called Lucifer, Bo I, Metr 5.11-16. Lucifer is the day star, Bo III, Metr l.9-12. Lucifer brings the day, Bo IV, Metr 6.15-18, and is the day's messenger, Tr III.1417-1418. [Esperus: Venus]
Lucifer is derived from lucem ferens, "light-bearing." Lucyfer is a spelling variant.