|Easton's Bible Dictionary|
House of Dagon.
(1.) A city in the low country or plain of Judah, near Philistia (Joshua 15:41); the modern Beit Degan, about 5 miles from Lydda.
(2.) A city near the south-east border of Asher (Joshua 19:27). It was a Philistine colony. It is identical with the modern ruined village of Tell D'auk.
Int. Standard Bible Encyclopedia
beth-da'-gon (bethdaghon; Bethdagon):
(1) A town in the Shephelah of Judah named with Gederoth, Naamah, and Makkedah (Joshua 15:41). It may be represented by the modern Beit Dijan, about 6 miles Southeast of Jaffa. This however is a modern site, and not in the Shephelah. Nearly 2 miles to the south is Khirbet Dajan, a Roman site. The connection in which it occurs leads us to expect a position farther Southeast
(2) A city on the border of Asher (Joshua 19:27) which Conder would identify with Tell D'auk, near the mouth of the Belus, in the plan of Acre.
The name seems to have been of frequent occurrence. There is a Beit Dejan about 6 miles East of Nablus, and Josephus speaks of a fortress called Dagon above Jericho (Ant., XII, viii, 1; BJ, I, ii, 3). This would seem to indicate a widespread worship of Dagon. But the name may mean "house of corn."
Bethdagon (2 Occurrences)
Joshua 15:41 And Gederoth, Bethdagon, and Naamah, and Makkedah; sixteen cities with their villages: (KJV)
Joshua 19:27 And turneth toward the sunrising to Bethdagon, and reacheth to Zebulun, and to the valley of Jiphthahel toward the north side of Bethemek, and Neiel, and goeth out to Cabul on the left hand, (KJV)