eureka

What it means

1. An exclamation indicating a sudden discovery.

   I rolled back the rug and eureka - there it was!

   3 more examples

   Eureka! I have found it! What I mean / To say is, not that love is idleness, / But that in love such idleness has been / An accessory, as I have cause to guess.

   1821, Byron, Don Juan

   "Eureka!" he cried, his teeth shining through his beard. "Gentlemen, you may congratulate me and we may congratulate each other. The problem is solved."

   1912, Arthur Conan Doyle, The Lost World […], London; New York, N.Y.: Hodder and Stoughton, →OCLC

   A page is turned - eureka, a snatch of tune / is playing itself, the piss-proud syllables / are unveiling a difficult prosody.

   1970, Peter Porter, The Sanitized Sonnets, The Last of England

In a sentence

I rolled back the rug and eureka - there it was!

Where it comes from

1. Ancient Greekεὕρηκα“I have found”
2. Englisheureka

From Ancient Greek εὕρηκα (heúrēka, “I have found”), perfect active indicative first person singular of εὑρίσκω (heurískō, “to find”). Archimedes supposedly exclaimed this when he figured out how to determine the density of an object. First use appears c. 1603 in a text by Philemon Holland.