The Collaborative International Dictionary of English v.0.48:

Appropriation \Ap*pro`pri*a"tion\, n. [L. appropriatio: cf. F.
   appropriation.]
   1. The act of setting apart or assigning to a particular use
      or person, or of taking to one's self, in exclusion of all
      others; application to a special use or purpose, as of a
      piece of ground for a park, or of money to carry out some
      object.
      [1913 Webster]

   2. Anything, especially money, thus set apart.
      [1913 Webster]

            The Commons watched carefully over the
            appropriation.                        --Macaulay.
      [1913 Webster]

   3. (Law)
      (a) The severing or sequestering of a benefice to the
          perpetual use of a spiritual corporation. Blackstone.
      (b) The application of payment of money by a debtor to his
          creditor, to one of several debts which are due from
          the former to the latter. --Chitty.
          [1913 Webster]

WordNet (r) 3.0 (2006):

appropriation
    n 1: money set aside (as by a legislature) for a specific
         purpose
    2: incorporation by joining or uniting [syn: annexation,
       appropriation]
    3: a deliberate act of acquisition of something, often without
       the permission of the owner; "the necessary funds were
       obtained by the government's appropriation of the company's
       operating unit"; "a person's appropriation of property
       belonging to another is dishonest"