fluor

Etymology

It is borrowed from Latin fluor (“flow, stream, flux”),^[2][3][4][5] from fluō (“to flow”) with the suffix -or.^[2][6][7] The mineral sense goes back to Agricola, who in 1546 uses the plural New Latin fluores to translate the early modern German mining word flusse, fluxes used in smelting.^[2][8][4] Merriam-Webster Unabridged likewise takes it as New Latin in the senses other than "flow", and as a translation of the German.^[9] Compare French flueur, recorded in the same mineral sense from 1554.^[2]

Earliest recorded meaning

Any of a class of minerals resembling gems but softer and more easily melted, useful as fluxes in smelting: 1610, in P. Holland's translation of W. Camden's Britain.^[2] Dictionary.com dates the word 1615–25,^[10] and Etymonline the mineral sense to the 1660s.^[4]

Semantic evolution

Having arrived as a miners' and alchemists' term, the word was also borrowed in the Latin senses of a flowing: menstruation from 1621, a flow or stream from 1642, and a fluid mass or the fluid state from 1654, all of them obsolete by the mid-18th century.^[2][3] Johnson (1755) had "a fluid state", quoting Newton, and "catamenia", but no mineral sense.^[11] Only the mineral use survived, narrowed in the 18th century to minerals containing what is now called fluorine, especially fluorspar: the OED dates this to 1772 and Etymonline to 1771.^[2][4] It is the base of fluorine, fluorite and fluorspar.^[5][12][6]

Timeline

• 1610 – a class of fusible minerals resembling gems (obsolete by 1756).^[2]
• 1621 – plural, menstruation (obsolete by 1724).^[2][3]
• 1642 – a flow or stream, an effluvium (obsolete by 1671).^[2] Merriam-Webster Unabridged has 1644.^[9]
• 1654 – a fluid mass, the humours of the body, the fluid state (obsolete by 1758).^[2][3]
• 1772 – a mineral containing fluorine, especially fluorspar.^[2] Etymonline dates it to 1771.^[4]

Meanings

Noun

1. (chiefly British) Fluorite or fluorspar.^{[9][13][10][2]}
2. (obsolete, 1610–1756) Any of a class of minerals resembling gems and used as fluxes in smelting.^[2][9]
3. (obsolete, 1621–1724) In the plural, menstruation.^[2][9][3]
4. (obsolete, 1642–1671) A flowing; a stream.^[2][9][3]
5. (obsolete, 1654–1758) A fluid mass, or the fluid state of a substance.^{[2][9][3][11]}

Word family

• fluorine
• fluorite
• fluorspar

Related words

• fluorescence
• fluorosis
• fluent
• flux
• fluid
• affluence
• fluorescent

Usage notes

A separate noun fluor (1945), a clipping of the first part of fluorescent, is a substance that fluoresces when struck by high-energy photons.^[2]

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
4. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
6. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ Skeat, Walter W. (1911), A Concise Etymological Dictionary of the English Language, new ed., Oxford: Clarendon Press
8. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
9. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
10. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
11. ^ a b Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
12. ^ Partridge, Eric (1966), Origins: A Short Etymological Dictionary of Modern English, 4th ed., London: Routledge & Kegan Paul
13. ^ Collins English Dictionary (2023), Glasgow: HarperCollins