Something remaining after removal of a part; a residue.(noun)
Law See residue.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "residuum" in a sentence
"The residuum is worth the market value of the item (not one-fifth the value)."
"In 4e, all you need to do is to remove the residuum from the belly, which you may or may not have removed already (I have)."
"Until those appear, in essance, residuum is just a special kind of very light gold pieces you can exchange for magical effects away from a store."