Heb. helel, literally, “shining one,” “brilliant one,” from the root halal, which means “to flash forth light,” “to shine,” “to be brilliant.” The name helel, and its equivalent in related languages, was commonly applied to the planet Venus as a morning star because of its unrivaled brilliance. Venus is the brightest of all the planets, and at maximum brilliance shines more than seven times brighter than Sirius, brightest, of all the fixed stars. When favorably situated, it is easily visible to the naked eye at noonday, and after dark it casts a shadow. The LXX renders helel as heōsphoros, “morning star,” literally, “bringer of the dawn,” the common Greek designation for Venus when it appeared in the morning sky. Compare the Heb. helel ben-shachar, “Lucifer, son of the morning,” literally, “shining one, son of dawn.”

 The name Lucifer comes from the Latin Vulgate, and means “light bearer.” The term, as here used, seems first to have been identified with Satan by Tertullian, Jerome, and other early Fathers of the church, and into common usage in this sense during the Middle Ages. In 2 Peter 1:19 Christ is referred to as phōsphoros, “day star”; literally, “light bearer.” In Rev. 22:16 He is called “the bright and morning star [literally, “dawn star,” or “star of the dawn”].” As applied to Satan, the various terms—helel, heōsphoros, Lucifer, etc.,—seem to reflect the thought of the high position he once held in heaven, next to Christ, and to imply that he is, even now, a rival of Christ. Strictly speaking, none of these terms is a proper name, though all have come to have that meaning; rather, they are attributive terms denoting the high state from which Lucifer fell. This description applies to Satan before his fall, as next to Christ in power and authority and head of the angelic hosts. For a further description of Satan (under the designation “king of Tyrus”) see Eze. 28:12-19.

 For the war between Christ and Satan, in which Satan was defeated and cast out to earth, see Rev. 12:7-9; see on Eze. 28:16-18.

 Compare vs. 4-6, 9-11.