I. ˈrezəˌd(y)ü noun
( -s )
Etymology: Middle English, from Middle French residu, from Latin residuum, from neuter of residuus left over, remaining, from residēre to sit back, remain — more at reside
: something that remains after a part is taken, separated, removed, or designated : remnant , remainder , rest : as
a. : the part of a testator's estate or of any part thereof remaining after the satisfaction of all debts, charges of administration, statutory allowances for support of a widow and children, and previous devises and bequests
b. obsolete : remainder 2b
c. : the part of a molecule that remains after the removal of a portion of its constituents : an atom or group regarded as a portion of a molecule : unit
fatty acid residues in fats
like starch they [glycogens] are based upon maltose residues, and like amylopectin … the branches contain less than half as many maltose units — J.W.McBain
— compare radical
d. : gruffs
II. noun
: the remainder after subtracting a multiple of a modulus from an integer or a power of the integer that can appear as the second of the two terms in an appropriate congruence