eureka

Pronunciation

• UK: /jəˈɹiː.kə/^[1]
• US: /jʊˈɹiː.kə/^[1]

Etymology

It is borrowed from Ancient Greek εὕρηκα (heúrēka, “I have found (it)”),^{[2][3][4][5][6]} the first person singular perfect active indicative of εὑρίσκω (heurískō, “to find”),^[3][6][5][7] the verb that also gave heuristic.^[3][8][9] The OED notes that the more correct transliteration, with an initial h, is rare.^[2] It is the exclamation said to have been uttered by Archimedes when he found how to test the purity of the gold in the crown of Hiero II, king of Syracuse.^[3][2][6][5]

Earliest recorded meaning

Archimedes' cry itself: the first English record is in Philemon Holland's translation of Plutarch's Moralia (1603).^[2][6][5] Barnhart and Ayto find it earlier in John Dee's Preface (1570), but written in Greek letters.^[6][8]

Semantic evolution

As the story goes, Archimedes saw the water in his bath overflow as he got in and realized that a crown of pure gold would displace a different amount of water from one of alloy; he leapt out shouting the word.^[8][10][9] From the start of its English use it was an exclamation of triumph at any discovery.^[11][2] Ayto thinks Henry Fielding was probably the first to naturalize it fully in English, in Joseph Andrews (1742).^[8] It became a noun in the mid 17th century, for a cry of eureka!.^[11] From 1853 it was used for a lucky discovery, a sense advertisers seized on to name their new products.^[2][11] In 1914 Eureka was registered as the trade name of a copper and nickel alloy used for resistance wire.^[2][11]

Timeline

• 1570 – quoted in Greek letters in John Dee's Preface.^[6][8]
• 1603 – the exclamation of Archimedes, in Holland's translation of Plutarch.^[2][6][5]
• mid 17th century – noun, a cry of eureka!.^[11]
• 1742 – an exclamation of delight at a discovery, in Fielding's Joseph Andrews.^[8]
• 1853 – a discovery to be proud of, often in the names of products.^[2]
• 1914 – the trade name of a copper-nickel alloy.^[2]

Meanings

Interjection

1. Used to express triumph or delight on finding or solving something: Eureka! The missing keys were in the fridge.^[5][12][11]

Noun

1. A fortunate discovery.^[11][2]
2. A cry of eureka!.^[11][13]
3. (trademark) An alloy of copper and nickel used for electrical filament and resistance wire.^[2][11]

Related words

• heuristic

Usage notes

Merriam-Webster's book of word histories points out that the bath story is known only from the Roman architect Vitruvius, two centuries after Archimedes, with no source from his own time, and that the detail of his running naked through the streets is probably invented, though he probably did weigh Hiero's crown in water.^[9]

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 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
5. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b c d e f g Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
7. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
8. ^ a b c d e f 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 Merriam-Webster's Book of Word Histories, Springfield, Mass.: Merriam-Webster
10. ^ Cresswell, Julia (2021), Oxford Dictionary of Word Origins, 3rd ed., Oxford: Oxford University Press
11. ^ a b c d e f g h i Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
12. ^ Collins English Dictionary (2023), Glasgow: HarperCollins
13. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press