Source : Webster's Revised Unabridged Dictionary (1913)

Worry \Wor"ry\, v. t. [imp. & p. p. {Worried}; p. pr. & vb. n.
   {Worrying}.] [OE. worowen, wirien, to strangle, AS. wyrgan in
   [=a]wyrgan; akin to D. worgen, wurgen, to strangle, OHG.
   wurgen, G. w["u]rgen, Lith. verszti, and perhaps to E.
   wring.]
   1. To harass by pursuit and barking; to attack repeatedly;
      also, to tear or mangle with the teeth.

            A hellhound that doth hunt us all to death; That dog
            that had his teeth before his eyes, To worry lambs
            and lap their gentle blood.           --Shak.

   2. To harass or beset with importunity, or with care an
      anxiety; to vex; to annoy; to torment; to tease; to fret;
      to trouble; to plague. ``A church worried with
      reformation.'' --South.

            Let them rail, And worry one another at their
            pleasure.                             --Rowe.

            Worry him out till he gives consent.  --Swift.

   3. To harass with labor; to fatigue. [Colloq.]

Source : WordNet®

worrying
     adj : causing distress or worry or anxiety; "distressing (or
           disturbing) news"; "lived in heroic if something
           distressful isolation"; "a disturbing amount of crime";
           "a revelation that was most perturbing"; "a new and
           troubling thought"; "in a particularly worrisome
           predicament"; "a worrying situation"; "a worrying time"
           [syn: {distressing}, {distressful}, {disturbing}, {perturbing},
            {troubling}, {worrisome}]

worrying
     n 1: the act of harassing someone [syn: {badgering}, {torment}, {bedevilment}]
     2: the act of moving something by repeated tugs or pushes;
        "vigorous worrying finally loosened the saw"