eu‧re‧ka /jʊˈriːkə/ 
 interjection humorous[
Date: 1600-1700; 
Language: Greek; 
Origin: heureka 'I have found', said by the Greek scientist Archimedes when he discovered a method of testing the purity of gold]
 used to show how happy you are that you have discovered the answer to a problem, found something etc 
 [TahlilGaran] Dictionary of Contemporary English ▲