Emily Dickinson Lexicon

FU'SION, n. [s as z. L. fusio; Fr. fusion; from L. fundo, fusum.]

1. The act or operation of melting or rendering fluid by heat, without the aid of a solvent; as, the fusion of ice or 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. Watery fusion, the melting of certain crystals by heat in their own water of crystalization. Chimistry.