Satan is a title used to refer to an evil being. It comes from Hebrew "HaSatan", which means "the adversary."
From Wikipedia: As an adjective, the
Latin word
lucifer meant "light-bringing" and was applied to the moon. As a noun, it meant "morning star", or, in
Roman mythology, its divine
personification as "the fabled son of
Aurora[46] and
Cephalus, and father of
Ceyx", or (in poetry) "day".
[6] The second of the meanings attached to the word when used as a noun corresponds to the image in
Greek mythology of
Eos, the goddess of dawn, giving birth to the morning star
Phosphorus.
Isaiah 14:12 is not the only place where the Vulgate uses the word
lucifer. The Vulgate uses the same word in contexts where it clearly has no reference to a fallen angel:
2 Peter 1:19 (meaning "morning star"),
Job 11:17 ("the light of the morning"),
Job 38:32 ("the signs of the zodiac") and
Psalms 110:3 ("the dawn").
[47] To speak of the morning star,
lucifer is not the only expression that the Vulgate uses: three times it uses
stella matutina:
Sirach 50:6 (referring to the actual morning star), and
Revelation 2:28 (of uncertain reference) and
22:16 (referring to
Jesus).
Other indications that in Christian tradition the Latin word
lucifer did not carry connotations of a fallen angel are the names of Bishops
Lucifer of Cagliari and
Lucifer of Siena, and its use in the
Easter Proclamation prayer to God regarding the
paschal candle:
Flammas eius lucifer matutinus inveniat: ille, inquam, lucifer, qui nescit occasum. Christus Filius tuus, qui, regressus ab inferis, humano generi serenus illuxit, et vivit et regnat in saecula saeculorum (May this flame be found still burning by the Morning Star: the one Morning Star who never sets, Christ your Son, who, coming back from death's domain, has shed his peaceful light on humanity, and lives and reigns for ever and ever). In the works of Latin grammarians, Lucifer, like Daniel, was discussed as an example of a personal name