The Collaborative International Dictionary of English v.0.48:

Treasury \Treas"ur*y\, n.; pl. Treasuries. [OE. tresorie, F.
   tr['e]sorerie.]
   1. A place or building in which stores of wealth are
      deposited; especially, a place where public revenues are
      deposited and kept, and where money is disbursed to defray
      the expenses of government; hence, also, the place of
      deposit and disbursement of any collected funds.
      [1913 Webster]

   2. That department of a government which has charge of the
      finances.
      [1913 Webster]

   3. A repository of abundance; a storehouse.
      [1913 Webster]

   4. Hence, a book or work containing much valuable knowledge,
      wisdom, wit, or the like; a thesaurus; as, " Maunder's
      Treasury of Botany."
      [1913 Webster]

   5. A treasure. [Obs.] --Marston.
      [1913 Webster]

   Board of treasury, the board to which is intrusted the
      management of all matters relating to the sovereign's
      civil list or other revenues. [Eng.] --Brande & C.

   Treasury bench, the first row of seats on the right hand of
      the Speaker in the House of Commons; -- so called because
      occupied by the first lord of the treasury and chief
      minister of the crown. [Eng.]

   Treasury lord. See Lord high treasurer of England, under
      Treasurer. [Eng.]

   Treasury note (U. S. Finance), a circulating note or bill
      issued by government authority from the Treasury
      Department, and receivable in payment of dues to the
      government.
      [1913 Webster]

WordNet (r) 3.0 (2006):

treasury
    n 1: the funds of a government or institution or individual
         [syn: treasury, exchequer]
    2: the government department responsible for collecting and
       managing and spending public revenues
    3: negotiable debt obligations of the United States government
       which guarantees that interest and principal payments will be
       paid on time [syn: Treasury, Treasury obligations]
    4: the British cabinet minister responsible for economic
       strategy [syn: Treasury, First Lord of the Treasury]
    5: the federal department that collects revenue and administers
       federal finances; the Treasury Department was created in 1789
       [syn: Department of the Treasury, Treasury Department,
       Treasury, United States Treasury]
    6: a depository (a room or building) where wealth and precious
       objects can be kept safely