1. [n]  an abrupt spasmodic movement
2. [n]  a sudden abrupt pull
3. [n]  a dull stupid fatuous person
4. [n]  (mechanics) the rate of change of velocity
5. [v]  make an uncontrolled, short, jerky motion; "his face is twitching"
6. [v]  throw or toss with a quick motion; "flick a piece of paper across the table"; "jerk his head"
7. [v]  pull, or move with a sudden movement; "He turned the handle and jerked the door open.."
8. [v]  jump vertically, with legs stiff and back arched, as of horses
9. [v]  move with abrupt, seemingly uncontrolled motions; "The patient's legs were jerkings"

Jerk
Jerk

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1. \Jerk\, v. t. [Corrupted from Peruv. charqui dried beef.]
   To cut into long slices or strips and dry in the sun; as,
   jerk beef. See {Charqui}.
   

2. \Jerk\, v. t. [imp. & p. p. {Jerked}; p. pr. & vb. n.
   {Jerking}.] [Akin to yerk, and perh. also to yard a measure.]
   1. To beat; to strike. [Obs.] --Florio.
   2. To give a quick and suddenly arrested thrust, push, pull,
      or twist, to; to yerk; as, to jerk one with the elbow; to
      jerk a coat off.
   3. To throw with a quick and suddenly arrested motion of the
      hand; as, to jerk a stone.
   

3. \Jerk\, v. i.
   1. To make a sudden motion; to move with a start, or by
      starts. --Milton.
   2. To flout with contempt.
   

4. \Jerk\, n.
   1. A short, sudden pull, thrust, push, twitch, jolt, shake,
      or similar motion.
            His jade gave him a jerk.             --B. Jonson.
   2. A sudden start or spring.
            Lobsters . . . swim backwards by jerks or springs.
                                                  --Grew.