(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.
" 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"
Emily: Yeah that's Frank he is new in town let's go talk to him.
B: Oh that's Frank.
A: Does he ever talk?
B: Haha yeah. He's really funny, but I think he said maybe four words to me the first couple times we met.
A: Oh hey that girl just went and kissed him. He's taken?
B: Yeah that's his girlfriend. She's so lucky. They'll probably get married, if he ever gets up the nerve to ask.