Definition: The act or operation of melting or rendering fluid by
heat; the act of melting together; as, the fusion of metals.
Definition: The state of being melted or dissolved by heat; a state
of fluidity or flowing in consequence of heat; as, metals in fusion.
Definition: The union or blending together of things, as, melted
together.
Definition: The union, or binding together, of adjacent parts or
tissues.