Oleums

Part of speech: noun

Definitions

1. A viscous liquid that contains concentrated sulfuric acid, used in chemical processes
2. A type of sulfuric acid that can create fumes and is often utilized for industrial purposes
3. A highly reactive and corrosive compound often involved in the manufacturing of various chemical products

Etymology: The plural "oleums" is simply the regular plural of "oleum," so the story belongs to the singular. That word began in ancient Greece as "élaion," the ordinary term for olive oil, and passed into Latin as "oleum" with the same meaning. The Latin word is an ancestor of English "oil," which is a doublet: two forms of one root that reached English by different routes, one through French and the other directly from Latin. The chemical sense is a German borrowing. German chemists adopted "Oleum" for the fuming sulfuric acid, a thick, oily-looking liquid, and the term carried into English from that source. The name is a loose metaphor, since the substance has nothing to do with olives, but it reflects how the liquid's heavy, oily texture struck early chemists.

Synonyms: oils, oleos