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.
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   2. Concession; compliance. [Obs.]
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   3. A yielding, or surrender, as of property or rights, to
      another person; the act of ceding.
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            A cession of the island of New Orleans. --Bancroft.
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   4. (Eccl. Law) The giving up or vacating a benefice by
      accepting another without a proper dispensation.
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   5. (Civil Law) The voluntary surrender of a person's effects
      to his creditors to avoid imprisonment.
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WordNet (r) 3.0 (2006):

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