The Collaborative International Dictionary of English v.0.48:

Rehabilitation \Re`ha*bil`i*ta"tion\ (-t?"sh?n), n. [Cf. LL.
   rehabilitatio, F. R['e]habilitation.]
   The act of rehabilitating, or the state of being
   rehabilitated. --Bouvier. Walsh.
   [1913 Webster]

WordNet (r) 3.0 (2006):

rehabilitation
    n 1: the restoration of someone to a useful place in society
    2: the conversion of wasteland into land suitable for use of
       habitation or cultivation [syn: reclamation, renewal,
       rehabilitation]
    3: vindication of a person's character and the re-establishment
       of that person's reputation
    4: the treatment of physical disabilities by massage and
       electrotherapy and exercises

Moby Thesaurus II by Grady Ward, 1.0:

65 Moby Thesaurus words for "rehabilitation":
   about-face, adjustive reaction, adjustment, backing, backsliding,
   clearance, clearing, destigmatization, destigmatizing,
   disenchantment, exculpation, explanation, flip-flop, fulfillment,
   improvement, instauration, integrated personality, justification,
   lapse, psychosynthesis, purgation, purging, rationalization,
   reactivation, readjustment, recidivation, recidivism, reclamation,
   reconditioning, reconstitution, reconversion, redintegration,
   reeducation, reenactment, reestablishment, reformation, regress,
   regression, reinstatement, reinstation, reinstitution,
   reinstruction, reinvestiture, reinvestment, relapse, repatriation,
   replacement, restitution, restoration, retrocession,
   retrogradation, retrogression, retroversion, return, returning,
   reversal, reverse, reversion, reverting, revulsion, slipping back,
   syntonic personality, turn, turnabout, vindication