Residuum (noun)

1. A remaining quantity or substance after a part has been removed or used.
2. Something that is left over after other parts have been taken away.

Origin:

Late middle english: from latin residuum "remnant, residue", from residere "remain".

Examples:

1. The residuum of the sale was a small collection of miscellaneous items.
2. The residuum of the estate was divided among the heirs.
3. The residuum of the reaction was analyzed in the lab.
4. The residuum of the dissolved solids was filtered out.
5. The residuum of the exploded star was studied by astronomers.