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.
EUREKA
Meaning of EUREKA in English
Webster English vocab. Английский словарь Webster. 2012