Source : Webster's Revised Unabridged Dictionary (1913)

Vacate \Va"cate\, v. t. [imp. & p. p. {Vacated}; p. pr. & vb. n.
   {Vacating}.] [L. vacare, vacatum, to be empty. See {Vacant}.]
   1. To make vacant; to leave empty; to cease from filling or
      occupying; as, it was resolved by Parliament that James
      had vacated the throne of England; the tenant vacated the
      house.

   2. To annul; to make void; to deprive of force; to make of no
      authority or validity; as, to vacate a commission or a
      charter; to vacate proceedings in a cause.

            That after act vacating the authority of the
            precedent.                            --Eikon
                                                  Basilike.

            The necessity of observing the Jewish Sabbath was
            Vacated by the apostolical institution of the Lord's
            Day.                                  --R. Nelson.

   3. To defeat; to put an end to. [R.]

            He vacates my revenge.                --Dryden.

Source : WordNet®

vacate
     v 1: leave (a job, post, post, or position) voluntarily; "She
          vacated the position when she got pregnant"; "The
          chairman resigned when he was found to have
          misappropriated funds" [syn: {resign}, {renounce}, {give
          up}]
     2: leave behind empty; move out of; "You must vacate your
        office by tonight" [syn: {empty}, {abandon}]
     3: annul by recalling or rescinding; "He revoked the ban on
        smoking"; "lift an embargo"; "vacate a death sentence"
        [syn: {revoke}, {annul}, {lift}, {countermand}, {reverse},
         {repeal}, {overturn}, {rescind}]