Investigator

·noun One who searches diligently into a subject.

investigator
investīgātor, ōris, m. [investigo], I he that searches or inquires into , an investigator (class...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
investigator
investīgātor ōris, m investigo, he that searches into, an investigator : rerum: antiquitatis. ...

An Elementary Latin Dictionary