oleum
/ˈoʊliəm/noun
oleum is a noun meaning “A solution of sulfur trioxide in sulfuric acid” (English Wiktionary, September 2026). It is spelled O-L-E-U-M, and it appears about once in every 18 million words in written English (wordfreq, 2021 data). The plural of oleum is oleums.
What does oleum mean?
noun
- 1
A solution of sulfur trioxide in sulfuric acid.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
How do you pronounce oleum?
- US /ˈoʊliəm/
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Forms of oleum
- oleums plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
How common is oleum?
Oleum appears about once in every 18 million words in written English, the 127,184th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
Oleum in Spanish, French, German and Portuguese
In the sense fuming sulfuric acid:
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does oleum come from?
From German Oleum, from Latin oleum (“olive oil”), from Ancient Greek ἔλαιον (élaion, “olive oil”). Doublet of oil.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).