Baal-Zebub is literally “the fly god,” or Baal of (the) fly.” Whether this name was given in honor or in contempt is not known. It may have been at first a name of contempt, but after, because of common use, lost its original significance. Some believe this god to have been of the medical idols of the Philistines, receiving its title from its imaginary influence over pestiferous insects, such as flies, that were said to infest Philistia. In Taylor’s Calmet [unknown] there is a curious paste representing a head of Jupiter, and having the appearance of a huge fly.
In his book (The Court of the Gentiles, 1672), the Rev. Theophilus Gale wrote: “The Phoenicians styled their principal god Baal Same, ‘the lord of heaven,’ (in the Phoenician language). The Jews called him Baal-Zebub, ‘lord of a fly.’ Scaliger [unknown] supposes that the original name was Baal-Zebahim, ‘lord of sacrifices,’ contracted, by way of contempt, to Baal-Zebub, ‘lord of flies,’ to mean he could not keep flies away from his sacrifices.”
It is thought by some that Beelzebul, which means dung-god, is a contemptuous designation of this Philistine Baal. See Matthew 10:25 and 12:24, Mark 3:22, and Luke 11:15, 18, and 19. According to many the name Beelzebub, as so rendered in those verses should have been rendered Beelzebul, which is a name for Satan. The Jews, being fond of a play on words, may have intentionally altered the name of this god. Some, however, define Beelzebul to mean “the lord of the dwelling” and deny any connection between Beelzebul of the New Testament and Baal-Zebub of the Old Testament.
Freeman, J. M., & Chadwick, H. J. (1998). Manners & customs of the Bible. “Rewritten and updated by Harold J. Chadwick”–Cover.; Includes index. (Rev. ed.].) (255). North Brunswick, NJ: Bridge-Logos Publishers.