thorium

Etymology

It is borrowed from New Latin thorium,^[2][3][4][5] named by its discoverer, the Swedish chemist Jöns Jakob Berzelius, in 1828–9,^[6][2][3][7] after Thor, the Norse god of thunder and war,^[2][5][6] in Old Norse Þórr,^[1][8] with the suffix -ium used in the names of metals.^[6][2][3] According to Etymonline and the Shorter Oxford it was formed from thorite, the Norwegian mineral from which it was extracted;^[3][9] Berzelius had earlier named its oxide thoria, in 1828.^[3][10] The OED notes that the French, having called the earth French thorine, named the metal thorinum, a name that prevailed in England for many years.^[6]

Earliest recorded meaning

The metallic element: 1832, in the Encyclopaedia Britannica.^[6][5][3] Dictionary.com dates the New Latin name to 1829.^[11]

Semantic evolution

The name has kept its single chemical sense.^[6][5] Weekley notes that the metal was adapted to incandescent gas mantles by Welsbach in 1885,^[7] and Collins still lists gas mantles among its uses, beside electronic equipment, magnesium alloys and nuclear power.^[4]

Timeline

• 1832 – the radioactive metallic element.^[6][5][3]

Meanings

Noun

1. A soft, silvery-white radioactive metallic chemical element with the symbol Th and atomic number 90, found in monazite and thorite and used as a nuclear fuel and in alloys and electronic equipment.^[4][5][6]

Word family

• mesothorium
• radiothorium
• thoria
• thoric
• thoron
• thorium dioxide
• thorium series

Related words

• Thor
• thorite
• Thursday
• thunder

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
3. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins
5. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b c d e f g h Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
7. ^ a b Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
8. ^ Barnhart, Robert K., ed. (1995), The Barnhart Concise Dictionary of Etymology, New York: HarperCollins
9. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
10. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
11. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House