illustrate

Etymology

It is borrowed from Latin illūstrō (“to light up, illuminate, make clear, make famous”), through its past participial stem,^{[2][3][4][5][6]} formed from in- (“in, upon”) and lūstrō (“to make bright; to purify”).^{[7][5][4][6][8]} Barnhart and Etymonline also see it partly as a back-formation from illustration.^[9][10] The AHD traces lūstrō to Proto-Indo-European *leuk- (“light”),^[7] and Ayto notes that it shares a base with lūmen (“light”) and lūx (“light”), the source of illuminate, and with English light;^[8][6] Merriam-Webster instead derives it from lūstrum (“purification”).^[5][11] The related Latin adjective illūstris (“shining, clear”) gave illustrious.^[8][12]

Earliest recorded meaning

To enlighten the mind, a figurative "shed light on": 1526, in William Bonde's Pylgrimage of Perfection;^[2][9] the past participle illustrate, "illuminated, enlightened", is recorded in the same text.^[2]

Semantic evolution

Ayto describes a passage from the literal "throw light on" to "elucidate", and then, in the 17th century, to "exemplify" and "add pictures to".^[8] In the 16th century the verb also meant to make a person or thing illustrious, to confer honour on it (1530),^[2][5] to make clear or explain (1538),^[2][6] and to adorn with bright colours (1592).^[2] The sense "to make clear by examples" is first recorded in 1612,^[2][9][10] and "to explain or decorate with pictures" in 1638, in Junius's Painting of the Ancients;^[2][9] Hoad dates the corresponding sense of illustration, a picture, to the 19th century.^[6] The physical sense "to light up" (1625–1717) and the adjective illustrate, "resplendent, illustrious" (1562–1705), have died out,^[2][3] and Collins keeps "to enlighten" only as archaic.^[11]

Timeline

• 1526 – to enlighten the mind.^[2][9]
• 1530 – to make illustrious, to confer honour on (now rare).^[2]
• 1538 – to make clear, explain.^[2]
• 1562 – adjective, resplendent, illustrious (until 1705).^[2]
• 1612 – to make clear by examples; to exemplify.^[2][9]
• 1625 – to light up physically (until 1717).^[2]
• 1638 – to explain or decorate with pictures.^[2][9]

Modern meaning

Verb

1. To provide a book, article or other text with pictures or drawings that explain or decorate it: She illustrated her grandson's storybook herself.
2. To make something clear by using examples, comparisons or analogies.
3. To be an example of something; to demonstrate: The delay illustrates how fragile the supply chain is.
4. (archaic) To enlighten.

Word family

• illustratable
• illustrator
• overillustrate
• reillustrate

Related words

• illustration
• illustrious
• illuminate
• luster
• lustrum

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 o p Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
4. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
5. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b c d e Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
7. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
8. ^ a b c d Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
9. ^ a b c d e f g Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
10. ^ a b Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
11. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins
12. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray