The Collaborative International Dictionary of English v.0.48:

Establishment \Es*tab"lish*ment\, n. [Cf. OF. establissement, F.
   ['e]tablissement.]
   1. The act of establishing; a ratifying or ordaining;
      settlement; confirmation.
      [1913 Webster]

   2. The state of being established, founded, and the like;
      fixed state.
      [1913 Webster]

   3. That which is established; as:
      (a) A form of government, civil or ecclesiastical;
          especially, a system of religion maintained by the
          civil power; as, the Episcopal establishment of
          England.
      (b) A permanent civil, military, or commercial, force or
          organization.
      (c) The place in which one is permanently fixed for
          residence or business; residence, including grounds,
          furniture, equipage, etc.; with which one is fitted
          out; also, any office or place of business, with its
          fixtures; that which serves for the carrying on of a
          business; as, to keep up a large establishment; a
          manufacturing establishment.
          [1913 Webster]

                Exposing the shabby parts of the establishment.
                                                  --W. Irving.
          [1913 Webster]

   Establishment of the port (Hydrography), a datum on which
      the tides are computed at the given port, obtained by
      observation, viz., the interval between the moon's passage
      over the meridian and the time of high water at the port,
      on the days of new and full moon.
      [1913 Webster]

WordNet (r) 3.0 (2006):

establishment
    n 1: the act of forming or establishing something; "the
         constitution of a PTA group last year"; "it was the
         establishment of his reputation"; "he still remembers the
         organization of the club" [syn: constitution,
         establishment, formation, organization,
         organisation]
    2: an organization founded and united for a specific purpose
       [syn: institution, establishment]
    3: the persons (or committees or departments etc.) who make up a
       body for the purpose of administering something; "he claims
       that the present administration is corrupt"; "the governance
       of an association is responsible to its members"; "he quickly
       became recognized as a member of the establishment" [syn:
       administration, governance, governing body,
       establishment, brass, organization, organisation]
    4: a public or private structure (business or governmental or
       educational) including buildings and equipment for business
       or residence
    5: any large organization
    6: (ecology) the process by which a plant or animal becomes
       established in a new habitat [syn: establishment, ecesis]
    7: the cognitive process of establishing a valid proof [syn:
       establishment, validation]