“Lobsters . . . swim backwards by jerks or springs.”
— Grew.
3.
A foolish, stupid, or otherwise contemptible person.[Slang]
4.
The lifting of a weight, in a single rapid motion, from shoulder height until the arms are outstretched above the head; distinguished from press in that the motion in a jerk is more rapid, and the body may be moved under the weight to assist completion of the movement; as, a clean and jerk of two hundred pounds.(Sport)
5.
Calisthenic exercises, such as push-ups or deep knee bends; also called physical jerks.[British]Also: physical jerks