The Collaborative International Dictionary of English v.0.48:

Abrogate \Ab"ro*gate\, a. [L. abrogatus, p. p.]
   Abrogated; abolished. [Obs.] --Latimer.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Abrogate \Ab"ro*gate\, v. t. [imp. & p. p. Abrogated; p. pr. &
   vb. n. Abrogating.] [L. abrogatus, p. p. of abrogare; ab +
   rogare to ask, require, propose. See Rogation.]
   1. To annul by an authoritative act; to abolish by the
      authority of the maker or his successor; to repeal; --
      applied to the repeal of laws, decrees, ordinances, the
      abolition of customs, etc.
      [1913 Webster]

            Let us see whether the New Testament abrogates what
            we so frequently see in the Old.      --South.
      [1913 Webster]

            Whose laws, like those of the Medes and Persian,
            they can not alter or abrogate.       --Burke.
      [1913 Webster]

   2. To put an end to; to do away with. --Shak.
      [1913 Webster]

   Syn: To abolish; annul; do away; set aside; revoke; repeal;
        cancel; annihilate. See Abolish.
        [1913 Webster]

WordNet (r) 3.0 (2006):

abrogate
    v 1: revoke formally

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "abrogate":
   abate, abolish, annihilate, annul, blot out, bring to naught,
   cancel, countermand, counterorder, disannul, discharge, dissolve,
   do away with, extinguish, invalidate, make void, negate, negative,
   nullify, obliterate, override, overrule, quash, recall, recant,
   renege, repeal, rescind, retract, reverse, revoke, ruin, set aside,
   suspend, undo, vacate, vitiate, void, waive, withdraw, wreck,
   write off