The Collaborative International Dictionary of English v.0.48:

Cession \Ces"sion\, n. [L. cessio, fr. cedere to give way: cf.
   F. Cession. See Cede.]
   1. A yielding to physical force. [Obs.] --Bacon.
      [1913 Webster]

   2. Concession; compliance. [Obs.]
      [1913 Webster]

   3. A yielding, or surrender, as of property or rights, to
      another person; the act of ceding.
      [1913 Webster]

            A cession of the island of New Orleans. --Bancroft.
      [1913 Webster]

   4. (Eccl. Law) The giving up or vacating a benefice by
      accepting another without a proper dispensation.
      [1913 Webster]

   5. (Civil Law) The voluntary surrender of a person's effects
      to his creditors to avoid imprisonment.
      [1913 Webster]

WordNet (r) 3.0 (2006):

cession
    n 1: the act of ceding [syn: cession, ceding]

Moby Thesaurus II by Grady Ward, 1.0:

88 Moby Thesaurus words for "cession":
   abalienation, abandonment, abdication, abjuration, abjurement,
   alienation, allowance, amortization, amortizement, assignation,
   assignment, bargain and sale, barter, bequeathal, capitulation,
   circumscription, concession, conferment, conferral, consignation,
   consignment, conveyance, conveyancing, deeding, deliverance,
   delivery, demise, dispensation, disposal, disposition,
   dropping out, dumping, enfeoffment, exception, exchange, exemption,
   extenuating circumstances, forgoing, forswearing, getting rid of,
   giving, giving in, giving over, giving up, grain of salt, grant,
   handing over, hedge, hedging, lease and release, letting go,
   limitation, mental reservation, modification, qualification,
   recantation, recedence, recession, release, relinquishment,
   renouncement, renunciation, reservation, resignation, restriction,
   retraction, retreat, riddance, sacrifice, sale, salvo, settlement,
   settling, special case, special treatment, specialness,
   specification, surrender, swearing off, trading, transfer,
   transference, transmission, transmittal, vesting, waiver,
   withdrawing, yielding



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

CESSION, contracts. Yielding up; release.
     2. France ceded Louisiana to the United States, by the treaty of Paris,
of April 30, 1803 Spain made a cession of East and West Florida, by the
treaty of February 22, 1819. Cessions have been severally made of a part of
their territory, by New York, Virginia, Massachusetts, Connecticut) South
Carolina, North Carolina, and Georgia. Vide Gord. Dig. art. 2236 to 2250.



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

CESSION, civil law. The, act by which a party assigns or transfers property
to a other; an assignment.



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

CESSION, eccl. law. When an ecclesiastic is created bishop, or when a parson
takes another benefice, without dispensation, the first benefice becomes
void by a legal cession, or surrender. Cowel, h.t.