Source : Webster's Revised Unabridged Dictionary (1913)

Yerk \Yerk\, v. t. [imp. & p. p. {Yerked}; p. pr. & vb. n.
   {Yerking}.] [See {Yerk}.]
   1. To throw or thrust with a sudden, smart movement; to kick
      or strike suddenly; to jerk.

            Their wounded steeds . . . Yerk out their armed
            heels at their dead masters.          --Shak.

   2. To strike or lash with a whip. [Obs. or Scot.]

Yerk \Yerk\, v. i.
   1. To throw out the heels; to kick; to jerk.

            They flirt, they yerk, they backward . . . fling.
                                                  --Drayton.

   2. To move a quick, jerking motion.

Yerk \Yerk\, n.
   A sudden or quick thrust or motion; a jerk.

Source : Free On-Line Dictionary of Computing

Yerk
     
         (After Yerkes Observatory) An {object-oriented}
        language based on a {Forth} {Kernel} with some major
        modifications.  It was originally known as {Neon}, developed
        and sold as a product by {Kriya Systems} from 1985 to 1989.
        Several people at The {University of Chicago} have maintained
        Yerk since its demise as a product.  Because of possible
        trademark conflict they named it Yerk, which is not an acronym
        for anything, but rather stands for Yerkes Observatory, part
        of the Department of Astronomy and Astrophysics at U of C.
     
        Version 3.62.
     
        {(ftp://oddjob.uchicago.edu/pub/Yerk/)}.
     
        E-mail: Bob Lowenstein .
     
        (1994-11-23)