" residue "

[Noun]  | "res*i*due" | \ ˈre-zə-ˌdü \

1: something that remains after a part is taken, separated, or designated or after the completion of a process : remnant, remainder : such as

2: the part of a testator's estate remaining after the satisfaction of all debts, charges, allowances, and previous devises and bequests

3: 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

Origin: 14th century ;

 Middle English, from Anglo-French, from Latin residuum, from neuter of residuus left over, from residēre to remain;

[Noun]  | "residue class" 

1: the set of elements (such as integers) that leave the same remainder when divided by a given modulus

Origin: 1948 ;

[Noun]  | "residue"