1. the process of melting or wasting away.
2. a melting together; the act of melting; fusion.
3. Medical: a processive wasting or melting away of the solid parts of the animal system with copious excretions of liquids by one or more passages; degeneration of tissue to a liquid state.
Etymology: Latin col- (together) + liquo, past participle of liquatus (to cause to melt).