The Collaborative International Dictionary of English v.0.48:

Abjure \Ab*jure"\, v. i.
   To renounce on oath. --Bp. Burnet.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Abjure \Ab*jure"\, v. t. [imp. & p. p. Abjured; p. pr. & vb.
   n. Abjuring.] [L. abjurare to deny upon oath; ab + jurare
   to swear, fr. jus, juris, right, law; cf. F. abjurer. See
   Jury.]
   1. To renounce upon oath; to forswear; to disavow; as, to
      abjure allegiance to a prince. To abjure the realm, is to
      swear to abandon it forever.
      [1913 Webster]

   2. To renounce or reject with solemnity; to recant; to
      abandon forever; to reject; repudiate; as, to abjure
      errors. "Magic I here abjure." --Shak.
      [1913 Webster]

   Syn: See Renounce.
        [1913 Webster]

WordNet (r) 3.0 (2006):

abjure
    v 1: formally reject or disavow a formerly held belief, usually
         under pressure; "He retracted his earlier statements about
         his religion"; "She abjured her beliefs" [syn: abjure,
         recant, forswear, retract, resile]

Moby Thesaurus II by Grady Ward, 1.0:

128 Moby Thesaurus words for "abjure":
   abandon, abdicate, acknowledge defeat, assert the contrary,
   back down, back out, backwater, belie, brush aside, cease, cede,
   chuck, chuck out, climb down, come off, contemn, contest,
   contradict, contravene, controvert, counter, crawfish out, cross,
   cry quits, cut out, decline, deny, desert, desist, desist from,
   despise, disaffirm, disallow, disapprove, disavow, discard,
   disclaim, discontinue, discount, disdain, disgorge, dismiss,
   disown, dispense with, dispose of, disprove, dispute, disregard,
   disuse, do without, drop, dump, eat crow, eat humble pie, except,
   exclude, forgo, forsake, forswear, gainsay, get along without,
   get rid of, give away, give over, give up, hand over,
   have done with, ignore, impugn, join issue upon, kiss good-bye,
   lay down, leave off, let go, make a sacrifice, nol-pros,
   not accept, not admit, not pursue with, nullify, oppose, palinode,
   part with, pass by, pass up, push aside, put behind one, quit,
   quitclaim, rebuff, recall, recant, refuse, refuse to admit,
   refuse to consider, refute, reject, relinquish, render up, renege,
   renounce, repel, repudiate, repulse, resign, retract, revoke,
   sacrifice, scout, shove away, spare, spurn, stop, surrender,
   swallow, swear off, take back, take issue with, throw away,
   throw out, throw up, turn away, turn out, unsay, vacate, waive,
   withdraw, yield