residuen.[F. rsidu, L. residuum, fr. residuus that is left behind, remaining, fr. residere to remain behind. See Reside, and cf. Residuum.]1. That which remains after a part is taken, separated, removed, or designated; remnant; remainder.()The residue of them will I deliver to the sword. (Jer. xv. 9.)If church power had then prevailed over its victims, not a residue of English liberty would have been saved. (I. Taylor.)2. (Law) That part of a testeator's estate wwhich is not disposed of in his will by particular and special legacies and devises, and which remains after payment of debts and legacies.()3. (Chem.) That which remains of a molecule after the removal of a portion of its constituents; hence, an atom or group regarded as a portion of a molecule; a moiety or group; -- used as nearly equivalent to radical, but in a more general sense.()()4. (Theory of Numbers) Any positive or negative number that differs from a given number by a multiple of a given modulus; thus, if 7 is the modulus, and 9 the given number, the numbers -5, 2, 16, 23, etc., are residues.()()