mathhead

A person who hangs around in back alleys and abandoned buildings doing math. The majority of mathheads will perform sex acts in exchange for math. They usually have various geometric shapes on their body, from staying up all night doing math. If you encounter one, they will usually ask you for money to support their math habit.

"Woah did you see that guy, he looks like a complete mathhead!"

"Yeah he must have been up all night doing calculus."