The Collaborative International Dictionary of English v.0.48:

Exemption \Ex*emp"tion\, n. [L. exemptio a removing: cf. F.
   exemption exemption.]
   The act of exempting; the state of being exempt; freedom from
   any charge, burden, evil, etc., to which others are subject;
   immunity; privilege; as, exemption of certain articles from
   seizure; exemption from military service; exemption from
   anxiety, suffering, etc.
   [1913 Webster]

WordNet (r) 3.0 (2006):

exemption
    n 1: immunity from an obligation or duty [syn: exemption,
         freedom]
    2: a deduction allowed to a taxpayer because of his status
       (having certain dependents or being blind or being over 65
       etc.); "additional exemptions are allowed for each dependent"
    3: an act exempting someone; "he was granted immunity from
       prosecution" [syn: exemption, immunity, granting
       immunity]

Moby Thesaurus II by Grady Ward, 1.0:

56 Moby Thesaurus words for "exemption":
   absolution, allowance, amnesty, cession, charter, circumscription,
   concession, diplomatic immunity, discharge, dispensation,
   exception, exclusion, exculpation, excuse, exoneration,
   extenuating circumstances, franchise, freedom, grace,
   grain of salt, grant, hedge, hedging, immunity, impunity,
   indemnity, legislative immunity, liberty, license, limitation,
   mental reservation, modification, nolle prosequi, non prosequitur,
   nonprosecution, pardon, patent, permission, privilege,
   qualification, redemption, release, remission, remission of sin,
   reprieve, reservation, restriction, salvo, shrift, sparing,
   special case, special treatment, specialness, specification, stay,
   waiver



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

EXEMPTION. A privilege which dispenses with the general rule; for example,
in Pennsylvania, and perhaps in all the other states, clergymen are exempt
from serving on juries. Exemptions are generally allowed, not for the
benefit of the individual, but for some public advantage.