The name Lucifer originally denotes the planet Venus,
emphasizing its brilliance. The Vulgate employs the word also for
"the light of the morning" (Job 11:17), "the signs of the zodiac"
(Job 38:32), and "the aurora" (Psalm 109:3). Metaphorically, the
word is applied to the King of Babylon (Isaiah 14:12) as preeminent
among the princes of his time; to the high priest Simon son of
Onias (Ecclesiasticus 50:6), for his surpassing virtue, to the
glory of heaven (Apocalypse 2:2
, by reason of its
excellency; finally to Jesus Christ himself (II Petr. 1:19;
Apocalypse 22:16; the "Exultet" of Holy Saturday) the true light of
our spiritual life.
The Syriac version and the version of Aquila derive the Hebrew noun
helel from the verb yalal, "to lament"; St. Jerome agrees with them
(In Isaiah 1:14), and makes Lucifer the name of the principal
fallen angel who must lament the loss of his original glory bright
as the morning star. In Christian tradition this meaning of Lucifer
has prevailed; the Fathers maintain that Lucifer is not the proper
name of the devil, but denotes only the state from which he has
fallen (Petavius, De Angelis, III, iii, 4).
http://www.newadvent.org/cathen/09410a.htm
