Boyd’s Bible Dictionary:

(god of the fly). The form of Baal worshipped at Ekron (2 Kings 1:16).

Concise Bible Dictionary:

Name of Baal as the god of Ekron, signifying “lord of the fly.” Josephus says with reference to king Ahaziah sending to this god, “Now it happened that Ahaziah, as he was coming down from the top of his house, fell down from it, and in his sickness sent to the Fly, which was the god of Ekron, for that was this god’s name” (Ant. 9, 2, 1). It was regarded as a preserver from poisonous flies, and hence as a healer of diseases (2 Kings 1:2-3, 6, 16). In the New Testament there is the similar name of BEELZEBUB to whom the miracles of the Lord in casting out demons were blasphemously attributed.

Strong’s Dictionary of Hebrew Words:

from 1168 and 2070; Baal of (the) Fly; Baal-Zebub, a special deity of the Ekronites
KJV Usage:

Jackson’s Dictionary of Scripture Proper Names:

lord of the fly

Potts’ Bible Proper Names:

God of wandering, or of flies:―a deity of the Ekronites, 2 Kings 1:2. {Dominus vagationis, vel muscarum}