The Collaborative International Dictionary of English v.0.48:

Dagon \Da"gon\ (d[=a]"g[o^]n), [Heb. D[=a]gon, fr. dag a fish:
   cf. Gr. Dagw`n.]
   The national god of the Philistines, represented with the
   face and hands and upper part of a man, and the tail of a
   fish. --W. Smith.
   [1913 Webster]

         This day a solemn feast the people hold
         To Dagon, their sea idol.                --Milton.
   [1913 Webster]

         They brought it into the house of Dagon. --1 Sam. v. 2.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dagon \Dag"on\ (d[a^]g"[o^]n), n. [See Dag a loose end.]
   A slip or piece. [Obs.] --Chaucer.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Dagon
    n 1: god of agriculture and the earth; national god of
         Philistines

Easton's 1897 Bible Dictionary:

Dagon
   little fish; diminutive from dag = a fish, the fish-god; the
   national god of the Philistines (Judg. 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 (Judg. 16:23-30) and Ashdod (1
   Sam. 5:1-7). (See FISH.)


Hitchcock's Bible Names Dictionary (late 1800's):

Dagon, corn; a fish