What is "watery fusion"

Fusion \Fu"sion\, n. [L. fusio, fr. fundere, fusum to pour, melt: cf. F. fusion. See Fuse, v. t., aud cf, Foison.]

1. The act or operation of melting or rendering fluid by heat; the act of melting together; as, the fusion of metals.

2. The state of being melted or dissolved by heat; a state of fluidity or flowing in consequence of heat; as, metals in fusion.

3. The union or blending together of things, as, melted together.

   The universal fusion of races, languages, and customs . . . had produced a corresponding fusion of creeds.
   --C. Kingsley.

   Watery fusion (Chem.) the melting of certain crystals by heat in their own water of crystallization.

4. (Biol.) The union, or binding together, of adjacent parts or tissues.