The residuum or deposit left after any chemical process.

That which remains after a process of combustion, evaporation, digestion, etc.; a deposit or sediment; a waste or residual product; = residuum, n. 3.

Chemistry. A white powder or residue. Obsolete.

Chemistry. spec. In chemical analysis: a solid deposit formed on charcoal, glass, etc., when a mineral or other substance is heated with a…