To curl your finger in a J shape and use it to lift someone's breast in an upward motion. Usually only done to fat kids or girls with big boobs.

A lame attempt at executing a donut. The driver ( from a standstill ) will lose traction, cut the wheel, and whip the car around 270 degrees, then continue to drive forward. Whereas a donut consists of almost a perfect 360 degrees of both rear tire marks. A donut requires some driving skill which most retards attempting it lack.

Its a "poop," that has curled and touched your ass without you knowing, leaving a shitsmear that follows you, until removed.

J Hook - Used in meteorology refering to the area of a thunderstorm that produces tornados. Usually associated with the "Dry line."