illustrious

Etymology

It is borrowed from Latin illūstris (“lighted, bright; distinguished, famous”) with the English suffix -ous.^{[2][3][4][5][6]} It replaced the earlier English adjective illustre, recorded before 1460, from Middle French illustre.^[6][7] The Latin adjective is probably a back-formation from illūstrō (“to light up; to embellish, make famous”),^[7][4][8] which is formed from in- (“in”) and lūstrō (“to make bright”), from Proto-Indo-European *leuk- (“light, brightness”).^[7]

Earliest recorded meaning

Of things, having the lustre of high rank or noble qualities; distinguished, famous: about 1566, in John Alday's translation of Pierre Boaistuau's Theatrum Mundi.^[2][6] Merriam-Webster dates the word to 1588 and Etymonline to the 1560s.^[4][7]

Semantic evolution

Used of persons, the word is recorded from 1598, in Shakespeare's Love's Labour's Lost.^[2] The literal Latin sense, lighted up or shining, came into English only later, from before 1626 to 1886, and "clearly evident" was used from 1654 to 1792; both are obsolete.^[2][9] Johnson (1755) defined it as "conspicuous; noble; eminent for excellence".^[10] In Cymbeline the Shakespeare folios print illustrious where the sense seems to be "not lustrous, dull", and editors have replaced it with other forms.^[2] Since 1858 Most Illustrious has been the special epithet of the Order of St Patrick.^[2]

Timeline

• c. 1566 – of things, distinguished, famous.^[2][6]
• 1598 – of persons, distinguished, renowned.^[2]
• before 1626 – shining, bright (obsolete by 1886).^[2]
• 1654 – clearly evident (obsolete by 1792).^[2]
• 1858 – Most Illustrious, the epithet of the Order of St Patrick.^[2]

Meanings

Adjective

1. Very distinguished and widely admired for rank, achievements or qualities; renowned, eminent: a scientist with an illustrious career.^[4][9][2]
2. Glorious; splendid: the illustrious victories of the campaign.^[9][2]
3. (obsolete, 1626–1886) Shining, bright.^[9][2]

Word family

• illustriously
• illustriousness
• unillustrious

Related words

• illustrate
• illustration
• lustre
• illustre

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ 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 Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
6. ^ a b c d Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
7. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
9. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins
10. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.