residuum

Short definition from Wiktionary

Noun

1. 1
   The residue, remainder or rest of something.
2. 2
   The solid material remaining after the liquid in which it was dissolved has been evaporated; a residue.
3. 3
   A binary function from [0,1] × [0,1] to [0,1] which is defined in terms of the t-norm as follows: x→y= sup z|z*x⩽y, where * denotes the t-norm function and sup denotes the supremum.
4. 4
   The residue of an estate.