Shorthand for No Beers Necessary. Used to describe a person so attractive that one wouldn't require a drink to inspire or prepare for denting headboards with them. Can be spoken as 'nibben'.
Guy 1: "Did you see the body on that chick? She's totally NBN!"
Guy 2: "Ummm... dude... she's got three eyes and one eyebrow. Ease up on the Jaeger! Nice rack, though."