(adjective): Honest or direct; Without euphemism.
(noun): A man who possesses tremendous variety of obscure knowledge or skill but does not display them frequently, thereby continuously surprising even close friends with his abilities.
" Hey man.... I didn't know your accountant brother could hot-wire a car!"
" Yeah. He's a Frank alright!"
" Anyone know where I can find a decent Taco in Hong Kong?"
" Hold on... Let me call my friend Frank in New York. He would know"