To provide a problem so interesting and difficult that the target is compelled to cease whatever they are doing (eating, reading, walking) in order to think about it.
Most effective on math professors, science majors, and similar.
Term coined by Randall Munroe, author of the webcomic XKCD.
"I started thinking about the effective resistance of an infinite network of resistors, but then I realized I had self-nerd-sniped."
"My friend totally nerd-sniped me! He suggested this problem and next thing I knew I was late to class!"