D defs.my
Entry 1 sense Webster, 1913

Eureka

/yo͝or-ēk'-ə/ · Eu·re·ka · IPA /jʊˈɹiː.kə/
01 The exclamation attributed to Archimedes, who is said to have cried out “Eureka! eureka!” (I have found it! I have found it!), upon suddenl…
  1. 1.
    The exclamation attributed to Archimedes, who is said to have cried out “Eureka! eureka!” (I have found it! I have found it!), upon suddenly discovering a method of finding out how much the gold of King Hiero's crown had been alloyed. Hence, an expression of triumph concerning a discovery.