1983 drama starring Gene Hackman and Rutger Hauer (6)
I believe the answer is:
eureka
(Other definitions for eureka that I've seen before include "Triumphant exclamation of discovery" , "Cry announcing a brilliant discovery" , "'I have found it!' (Greek)" , "Exclamation of triump from Archimedes" , "county seat in 23 [CALIFORNIA]" .)