An abbreviation for; You Big Nut.
Noun, Slang.
1. A term used to describe
someone who is clumsy, off-kilter, or somewhat
foolish.
On their way to
lunch...
Mr. Valentine: Mr. Malchow, I think I forgot my
wallet at
the office.
Mr. Malchow: Well, why'd you do that YBN?
Mr. Valentine: Because I'm a big nut.