\Hark\, v. i. [OE. herken. See {Hearken}.]
To listen; to hearken. [Now rare, except in the imperative
form used as an interjection, Hark! listen.] --Hudibras.

{Hark away!} {Hark back!} {Hark forward!} (Sporting), cries
   used to incite and guide hounds in hunting.

{To hark back}, to go back for a fresh start, as when one has
   wandered from his direct course, or made a digression.

         He must have overshot the mark, and must hark back.
         Haggard. He harked back to the subject. --W. E.
                                               Norris.