Beelzebub
(1) The fly-god, a god worshipped in the Philistine town of Ekron (II Kings 1:3) (2) An evil spirit. (3) Any person of fiendish cruelty, who is nicknamed by his adversaries, or, in contempt of moral sentiment, appropriates the appellation to himself and cherishes it as if it were an honorable title.
Entry from Everybody's Cyclopedia, 1912.