Definition of "Jerk" :

noun: a sudden abrupt pull

noun: an abrupt spasmodic movement

noun: raising a weight from shoulder height to above the head by straightening the arms

noun: meat (especially beef) cut in strips and dried in the sun

noun: a dull stupid fatuous person

noun: (mechanics) the rate of change of acceleration

verb: make an uncontrolled, short, jerky motion

verb: throw or toss with a quick motion

"Jerk his head."

verb: pull, or move with a sudden movement

"He turned the handle and jerked the door open."

verb: jump vertically, with legs stiff and back arched

verb: move with abrupt, seemingly uncontrolled motions

"The patient's legs were jerkings."