The Collaborative International Dictionary of English v.0.48:

Jerk \Jerk\, v. t. [imp. & p. p. Jerked (j[~e]rkt); p. pr. &
   vb. n. Jerking.] [Akin to yerk, and perh. also to yard a
   measure.]
   [1913 Webster]
   1. To beat; to strike. [Obs.] --Florio.
      [1913 Webster]

   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.
      [1913 Webster]

   3. To throw with a quick and suddenly arrested motion of the
      hand; as, to jerk a stone.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Jerking \Jerk"ing\, n.
   The act of pulling, pushing, or throwing, with a jerk. --
   Jerk"ing*ly, adv.
   [1913 Webster]

WordNet (r) 3.0 (2006):

jerking
    adj 1: lacking a steady rhythm; "an arrhythmic heartbeat" [syn:
           arrhythmic, jerking, jerky]
    n 1: an abrupt spasmodic movement [syn: jerk, jerking,
         jolt, saccade]