radiant

Etymology

It is borrowed from Latin radiāns (“shining, beaming”), stem radiant-,^[2][3][4][5] the present participle of radiō (“to beam, shine, emit rays”),^[3][2][4][6] from radius (“beam, ray”).^[7][8][9] Barnhart thinks it may have come through Middle French radiant, but more likely directly from Latin.^[6] The OED compares French radiant, recorded in Old French in the first half of the 13th century, Spanish radiante and Italian radiante.^[2] The Latin noun is also the source, through French, of ray.^[7]

Earliest recorded meaning

Sending out rays of light, shining brightly: about 1450.^[2][6][3]

Semantic evolution

From the early 16th century the word was used of light appearing as rays and, figuratively, of beauty and other qualities that seem to shine outward;^[2][3] from 1508 to 1862 it could also describe strong, fierce heat, especially the sun's.^[2] From 1589 it described bright, beaming eyes or looks, and later a person, especially a young woman or a bride, glowing with joy or health.^[2] Johnson (1755) defined it as shining, sparkling and emitting rays.^[10] Science added more senses: in botany, spreading out from a centre (1737), and in physics, of heat, transmitted by radiation (1780), a sense modelled on German strahlend in a translation of Scheele.^[2] The noun meant in optics a point from which light radiates (1714 in Etymonline, 1728 in the OED),^[3][2] and in astronomy the point in the sky from which the meteors of a shower seem to come, a use that followed the great meteor shower of November 1833.^[3][2] The noun radiance is first recorded in Shakespeare's All's Well that Ends Well (1601).^[6]

Timeline

• c. 1450 – sending out rays of light, shining.^[2][6]
• 1508 – of heat, strong, fierce (obsolete by 1862).^[2]
• 1509 – of light, beauty or qualities, splendid, dazzling.^[2][3]
• 1589 – of eyes or looks, beaming with joy or love.^[2]
• 1714 – noun, in optics, a point from which light radiates.^[3]
• 1737 – in botany, spreading from a common centre.^[2]
• 1780 – of heat, transmitted by radiation.^[2]
• by 1834 – noun, in astronomy, the radiant of a meteor shower (1864 in the OED).^[3][2]
• 1917 – designed to give out radiant heat.^[2]

Meanings

Adjective

1. Sending out light; shining brightly: a radiant morning sun.^[11][12][2]
2. Glowing with joy, love or health: The winner gave a radiant smile.^[11][2][12]
3. Sent out by radiation: radiant heat.^[11][2]
4. Giving out heat by radiation: a radiant heater.^[11][2]
5. (botany) Spreading out from a common centre.^[2]

Noun

1. (astronomy) The point in the sky from which the meteors of a meteor shower seem to come.^[12][2][3]
2. A point or object from which light or heat radiates.^[2][3][12]
3. A heating element of a radiant heater.^[2]

Word family

• radiantly
• radiance
• radiancy
• superradiant
• unradiant
• radiant energy
• radiant heat

Related words

• radiate
• radiation
• radius
• ray

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 s t u v w x y z Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g h i j k Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
5. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
6. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
7. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
8. ^ Skeat, Walter W. (1911), A Concise Etymological Dictionary of the English Language, new ed., Oxford: Clarendon Press
9. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
10. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
11. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins
12. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster