Part of speech: noun
Origin: Latin, 17th century
A substance or thing that remains or is left behind, in particular, a chemical residue.
Examples of Residuum in a sentence
"All that was left after the chemical reaction was a sticky green residuum."
"Johan soaked his saucepan to soften the chili residuum burned to the bottom."
“Residuum” is borrowed directly from the Latin, in which it referred to “something that remains.”
Did you Know?
“Residuum” is a nearly identical word to “residue,” but the two are not quite the same. “Residuum” began its life in scholarly writing as a direct reference to the Latin root word “residuum,” and for many years it was used interchangeably with the early English word “residue.” (“Residue” appeared in English roughly 250 years earlier than “residuum.”) In the world of 19th-century chemistry, however, the two words split. “Residue” referred to any sort of leftover remainder or byproduct, and “residuum” took on the specific meaning of waste products left over following a chemical reaction.