Source : Webster's Revised Unabridged Dictionary (1913)

Dog \Dog\, v. t. [imp. & p. p. {Dogged}; p. pr. & vb. n.
   {Dogging}.]
   To hunt or track like a hound; to follow insidiously or
   indefatigably; to chase with a dog or dogs; to worry, as if
   by dogs; to hound with importunity.

         I have been pursued, dogged, and waylaid. -- Pope.

         Your sins will dog you, pursue you.      --Burroughs.

         Eager ill-bred petitioners, who do not so properly
         supplicate as hunt the person whom they address to,
         dogging him from place to place, till they even extort
         an answer to their rude requests.        -- South.

Source : WordNet®

dogging
     adj : relentless and indefatigable in pursuit or as if in pursuit;
           "impossible to escape the dogging fears" [syn: {persisting}]

dog
     n 1: a member of the genus Canis (probably descended from the
          common wolf) that has been domesticated by man since
          prehistoric times; occurs in many breeds; "the dog
          barked all night" [syn: {domestic dog}, {Canis
          familiaris}]
     2: a dull unattractive unpleasant girl or woman; "she got a
        reputation as a frump"; "she's a real dog" [syn: {frump}]
     3: informal term for a man; "you lucky dog"
     4: someone who is morally reprehensible; "you dirty dog" [syn:
        {cad}, {bounder}, {blackguard}, {hound}, {heel}]
     5: a smooth-textured sausage of minced beef or pork usually
        smoked; often served on a bread roll [syn: {frank}, {frankfurter},
         {hotdog}, {hot dog}, {wiener}, {wienerwurst}, {weenie}]
     6: a hinged catch that fits into a notch of a ratchet to move a
        wheel forward or prevent it from moving backward [syn: {pawl},
         {detent}, {click}]
     7: metal supports for logs in a fireplace; "the andirons were
        too hot to touch" [syn: {andiron}, {firedog}, {dog-iron}]
     [also: {dogging}, {dogged}]

dog
     v : go after with the intent to catch; "The policeman chased the
         mugger down the alley"; "the dog chased the rabbit" [syn:
          {chase}, {chase after}, {trail}, {tail}, {tag}, {give
         chase}, {go after}, {track}]
     [also: {dogging}, {dogged}]

dogging
     See {dog}