fusion Definition

1. chem.
The process of melting, whereby a substance changes from a solid to a liquid.
Thesaurus: melting, liquefaction, liquefying, heating, smelting.
2. The act of joining together.

Thesaurus: union, unification, amalgamation, blend, coalition, synthesis, federation, integration, merger, commingling, mixture, alloy.
3. nuclear physics.
See under nuclear fusion.