Lucifer was originally a Latin word meaning "light-bearer" (from lux, "light", and ferre, "to bear, bring"), a Roman astrological term for the "Morning Star", the planet Venus.
"I will put enmity between you and the woman, and between your offspring and her offspring; he shall bruise your head, and you shall bruise his heel." Genesis 3:15 ESV
The word Lucifer was the direct translation of the Greek eosphorus ("dawn-bearer"; cf. Greek phosphorus, "light-bearer") used by Jerome in the Vulgate. In that passage, Isaiah 14:12, it referred to one of the popular honorific titles of a Babylonian king; however, later interpretations of the text, and the influence of embellishments in works such as Dante's The Divine Comedy and John Milton's Paradise Lost, led to the common idea in Christian mythology and folklore that Lucifer was a poetic appellation of Satan.