The Collaborative International Dictionary of English v.0.48:

Reversal \Re*ver"sal\, a. [See Reverse.]
   Intended to reverse; implying reversal. [Obs.] --Bp. Burnet.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Reversal \Re*ver"sal\, n. [From Reverse.]
   1. The act of reversing; the causing to move or face in an
      opposite direction, or to stand or lie in an inverted
      position; as, the reversal of a rotating wheel; the
      reversal of objects by a convex lens.
      [1913 Webster]

   2. A change or overthrowing; as, the reversal of a judgment,
      which amounts to an official declaration that it is false;
      the reversal of an attainder, or of an outlawry, by which
      the sentence is rendered void. --Blackstone.
      [1913 Webster]

WordNet (r) 3.0 (2006):

reversal
    n 1: a change from one state to the opposite state; "there was a
         reversal of autonomic function"
    2: an unfortunate happening that hinders or impedes; something
       that is thwarting or frustrating [syn: reverse, reversal,
       setback, blow, black eye]
    3: turning in an opposite direction or position; "the reversal
       of the image in the lens" [syn: reversal, turn around]
    4: a decision to reverse an earlier decision [syn: reversal,
       change of mind, flip-flop, turnabout, turnaround]
    5: a judgment by a higher court that the judgment of a lower
       court was incorrect and should be set aside [ant:
       affirmation]
    6: turning in the opposite direction [syn: reversion,
       reverse, reversal, turnabout, turnaround]
    7: the act of reversing the order or place of [syn:
       transposition, reversal]
    8: a major change in attitude or principle or point of view; "an
       about-face on foreign policy" [syn: about-face, volte-
       face, reversal, policy change]

Moby Thesaurus II by Grady Ward, 1.0:

204 Moby Thesaurus words for "reversal":
   abolishment, abolition, about-face, about-turn, abrogation,
   accommodation, adaptation, adjustment, afterthoughts, alchemy,
   alteration, amelioration, annulment, apostasy, assimilation,
   assumption, atavism, back track, back trail, backing, backing off,
   backing out, backing up, backset, backsliding, backup,
   backward deviation, bafflement, balk, becoming, better thoughts,
   betterment, bouleversement, break, cancel, canceling, cancellation,
   cassation, change, change of heart, change of mind, change-over,
   changeableness, check, checkmate, comedown, confusion,
   constructive change, continuity, conversion, countermand,
   counterorder, defeasance, defection, degeneration,
   degenerative change, descent, deterioration, deviation, difference,
   discomfiture, discontinuity, disenchantment, divergence,
   diversification, diversion, diversity, down, ectropion, eversion,
   falling back, fitting, flip, flip-flop, foil, frustration,
   gradual change, growth, improvement, introversion, intussusception,
   invagination, invalidation, inversion, lapse, mature judgment,
   melioration, mitigation, modification, modulation, naturalization,
   nullification, overthrow, overturning, passage, progress,
   pronation, qualification, radical change, re-creation,
   re-formation, realignment, rebuff, recall, recantation,
   recidivation, recidivism, reclamation, reconversion, recrudescence,
   recurrence, redesign, reduction, reform, reformation, regress,
   regression, rehabilitation, reinstatement, relapse, remaking,
   renege, renewal, repeal, repulse, rescinding, rescindment,
   rescission, reshaping, resolution, restitution, restoration,
   restructuring, resupination, retraction, retrocession,
   retroflexion, retrogradation, retrogression, retroversion, return,
   returning, reverse, reverse of fortune, reversing, reversion,
   reverting, revival, revivification, revocation, revoke, revokement,
   revolution, revulsion, right-about, right-about-face, rout,
   second thoughts, setback, setting aside, severe check, shift,
   slipping back, sudden change, supination, suspension, swingaround,
   switch, switch-over, tergiversating, tergiversation, throwback,
   topsy-turviness, topsy-turvydom, total change, transformation,
   transit, transition, transposal, transposition, turn, turnabout,
   turnaround, turning, turning back, turning backwards,
   turning inside out, turning into, turning inward, turning over,
   upheaval, vacation, vacatur, variation, variety, violent change,
   voidance, voiding, volte-face, waiver, waiving, withdrawal,
   worsening, write-off



Bouvier's Law Dictionary, Revised 6th Ed (1856):

REVERSAL, international law. First. A declaration by which a sovereign
promises that he will observe a certain order, or certain conditions, which
have been once established, notwithstanding any changes that may happen to
cause a deviation therefrom; as, for example, when the French court,
consented for the first time, in 1745, to grant to Elizabeth, the Czarina of
Russia, the title of empress, exacted as a reversal, a declaration
purporting that the assumption of the title of an imperial government, by
Russia, should not derogate from the rank which France had held towards
her. Secondly. Those letters are also termed reversals, Litterae Reversales,
by which a sovereign declares that, by a particular act of his, he does not
mean to prejudice a third power. Of this we have an example in history:
formerly, the emperor of Germany, whose coronation, according to the golden
ball, ought to have been solemnized at Aix-la-Chapelle, gave to that city
when he was crowned elsewhere, reversals, by which he declared that such
coronation took place without prejudice to its rights, and without drawing
any consequences therefrom for the future.