When you have a crush on a person's brain, with complete disregard to appearance, availability, etc.
Laura has a braincrush on Thomas Jefferson.
av awesomeaardvark 21 oktober 2009
wanting someone purely for their mind - has nothing to do with sexual attraction.
"i have such a brain crush on this kid in my philoshophy class. sure hes 5'3" and clearly never combs his hair, but he is so witty and articulate."
av woundedgazelle 12 december 2005