<p><strong>Noun</strong></p><ul><li>something that remains after a part is removed, disposed of, or used; remainder; rest; remnant.</li><li>Synonyms: residuum.</li><li>Chemistry: residuum (def 2).</li><li>an atom or group of atoms considered as a group or part of a molecule.</li><li>that part remaining as a solid on a filter paper after a liquid passes through in the filtration procedure.</li><li>Law: the part of a testator's estate that remains after the payment of all debts, charges, special devises, and bequests.</li><li>Mathematics: the coefficient of the term with exponent −1 in a Laurent series of a function of a complex variable.</li><li>a number related to a given number by a congruence.</li></ul>