Someone who is better than you at something you are good at.
<Marketer>Oh, Jimmy the computer guy? He's just a geek. But my boss Karen is *Super* smart.
<Christian>Jeremy is such a smart person! Give him any just about any religious quote, and he can tell you who said it and usually which book of the bible it came from!
<Scientist>Bob's a smart guy. His conclusions are always in line with the numbers and he seldom resorts to philosophical arguments to prove his points.
<Fashion snob>My auto mechanic is such an idiot. If he cleaned up the waiting room a bit, replaced some old furniture, and put some interesting things on the walls, he could double his business!
<Cooler mate>So why do you use him?
<Fashion snob>He's good with cars!