iridescent

Etymology

It is formed from English irid- + -escent,^[2][3][4] the first part being from Latin īris (“rainbow; genitive īridis”),^{[5][6][7][8][9]} from Ancient Greek ἶρις (îris, “rainbow”),^[10][1] a word of uncertain origin that was traditionally derived from Proto-Indo-European *wei- (“to bend, turn, twist”).^[5] The suffix comes from Latin -escens, the ending of present participles of certain verbs, meaning beginning or becoming.^[5] Compare French iridescent.^[7]

Earliest recorded meaning

Coloured like the rainbow: Etymonline dates the word to 1784.^[5] The OED's first quotation is from 1794, in Kirwan's Elements of Mineralogy,^[7] and Barnhart and Merriam-Webster Unabridged give 1796.^[6][2]

Semantic evolution

The word's early record is in a work on minerals, and it described the play of rainbow colours on a surface,^[7] often compared to the colours on soap bubbles.^[7][8] A figurative use is recorded from 1864,^[7] as in "iridescent froth", J. S. Blackie's phrase for fictions without a deep moral meaning.^[8] The noun iridescence follows in 1804,^[6] probably formed by changing the suffix,^[6] and the rare verb iridesce, a back-formation, in 1868.^[5][8] Merriam-Webster Unabridged also records a noun, iridescent, for a fabric, trimming or accessory of that kind.^[2]

Timeline

• 1784 – rainbow-coloured.^[5] The OED's first quotation for colours like those of the rainbow is from 1794.^[7]
• 1804 – the noun iridescence.^[6]
• 1864 – figurative use.^[7]
• 1868 – the verb iridesce, a back-formation.^[5]

Meanings

Adjective

1. Showing shimmering rainbow colours that shift with the light or the viewer's position, as on a soap bubble: an iridescent dragonfly wing.^[4][2][7]
2. Figuratively, having a gleaming or glittering quality.^[2][7]

Noun

1. A fabric, trimming or accessory with such a shimmering surface.^[2]

Word family

• iridescently
• noniridescent
• uniridescent
• iridescence

Related words

• iris
• iridium

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
3. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
4. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins
5. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ a b c d e Barnhart, Robert K., ed. (1995), The Barnhart Concise Dictionary of Etymology, New York: HarperCollins
7. ^ a b c d e f g h i j Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
8. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
9. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
10. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.