ETYM AS. deófol, deóful; akin to German teufel, Goth. diabaúlus; all from Latin diabolus the devil, Greek daimon the devil.
1. One of the evil spirits of traditional Jewish and Christian belief; SYN. fiend, demon, daemon, daimon.
2. A word used in exclamations of confusion; SYN. deuce, dickens.
In Jewish, Christian, and Muslim theology, the supreme spirit of evil (Beelzebub, Lucifer, Iblis), or an evil spirit generally.
The devil, or Satan, is mentioned only in the more recently written books of the Old Testament, but the later Jewish doctrine is that found in the New Testament. The concept of the devil passed into the early Christian church from Judaism, and theology until at least the time of St Anselm represented the Atonement as primarily the deliverance, through Christ's death, of mankind from the bondage of the devil. Jesus recognized as a reality the kingdom of evil, of which Satan or Beelzebub was the prince. In the Middle Ages the devil in popular superstition assumed the attributes of the horned fertility gods of paganism, and was regarded as the god of witches. The belief in a personal devil was strong during the Reformation, and the movement's leader Luther regarded himself as the object of a personal Satanic persecution. With the development of liberal Protestantism in the 19th century came a strong tendency to deny the existence of a positive spirit of evil, and to explain the devil as merely a personification.
However, the traditional conception was never abandoned by the Roman Catholic church, and theologians such as C S Lewis have maintained the existence of a power of evil.
In Muslim theology, Iblis is one of the jinn (beings created by Allah from fire), who refused to prostrate himself before Adam, and who tempted Adam and his wife Hawwa (Eve) to disobey Allah, an act which led to their expulsion from Paradise. He continues to try to lead people astray, but at the Last Judgment he and his hosts will be consigned to hell.