When you have a crush on a person's brain, with complete disregard to appearance, availability, etc.
Laura has a braincrush on Thomas Jefferson.
ayon kay awesomeaardvark ika-21 ng Oktubre, 2009
1 more definition
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."
ayon kay woundedgazelle ika-12 ng Disyembre, 2005