The crushing or screwing around with other people's minds. Often due to a flare of emotion of one party in a conversation.
Damn, I was talking to Shauney and she was dealing some dope ass mind crush on some fool.
A term used in Yu Gi Oh: The Abridged Series, to denote a sequence when Yami sticks his hand out, and the whole screen turns like a photo-negative then shatters. Apparently it destroys someone's mind.
Joe: Well, Mac kept telling me about his "awesome skillz" so I mind crushed him.
Crushes one develops on another's intellectual fortitude that, while occasionally pursuable, are not actively pursued due to the inherent irrationality of said longings -- and the fact you don't talk to him/her in real life or, well, at all. Targets often include former MIT linguistics professors and random guys who write for scholarly/incredibly esoteric publications, and maybe you.
"I have such a mindcrush on Steven Pinker."