ETYM French résidu, Latin residuum, from residuus that is left behind, remaining, from residere to remain behind. Related to Reside, Residuum.
Matter that remains after something has been removed.
In chemistry, a substance or mixture of substances remaining in the original container after the removal of one or more components by a separation process.
The nonvolatile substance left in a container after evaporation of liquid, the solid left behind after removal of liquid by filtration, and the substances left in a distillation flask after removal of components by distillation, are all residues.