Investigate someone thoroughly, especially in order to ensure that they are suitable for a job requiring secrecy, loyalty, or
trustworthiness.
Derives from late 14th century Norway where you would investigate and check if a visitor was a
vette (a supernatural being or troll) before letting them into your home.
The origin of the word is
Proto-Germanic *wihti and is related to the german word "Wicht" and english "wight" and Old Norse ; «vǣt(t)r».