Dagon

Fish-god, a national idol of the Philistines, with temples at Gaza, Ashdid, etc., 1 Chronicles 10:10. The temple at Gaza was destroyed by Samson, Judges 16:21-30. In that at Ashdod, Dagon twice miraculously fell down before the ark of God; and in the second fall his head and hands were broken off, leaving only the body, which was in the form of a large fish, 1 Samuel 5:1-9. See Joshua 15:41; 19:27. There were other idols of like form among the ancients, particularly the goddess Derceto of Atergatis; and a similar form or "incarnation" of Vishnu is at this day much worshipped in India, and like Dagon is destined to be prostrated in the dust before the true God.

Source: ATS Bible Dictionary
Dagon

Little fish; diminutive from dag = a fish, the fish-god; the national god of the Philistines (Judges 16:23). This idol had the body of a fish with the head and hands of a man. It was an Assyrio-Babylonian deity, the worship of which was introduced among the Philistines through Chaldea. The most famous of the temples of Dagon were at Gaza (Judges 16:23-30) and Ashdod (1 Samuel 5:1-7). (See FISH .)

Source: Easton's Bible Dictionary
Dagon

(a fish ), apparently the masculine, (1 Samuel 5:3,4) correlative of Atargatis, was the national god of the Philistines. The most famous temples of Dagon were at Gaza, (Judges 16:21-30) and Ashdod. (1 Samuel 5:5,6; 1 Chronicles 10:10) The latter temple was destroyed by Jonathan in the Maccabaean wars. Traces of the worship of Dagon likewise appear in the names Caphar-dagon (near Jamnia) and Beth-dagon in Judah, (Joshua 15:41) and Asher. (Joshua 19:27) Dagon was represented with the face and hands of a man and the tail of a fish. (1 Samuel 5:5) The fish-like form was a natural emblem of fruitfulness, and as such was likely to be adopted by seafaring tribes in the representation of their gods.

Source: Smith's Bible Dictionary