The Collaborative International Dictionary of English v.0.48:

Circumscription \Cir`cum*scrip"tion\, n. [L. circumscriptio. See
   Circumscribe.]
   1. An inscription written around anything. [R.] --Ashmole.
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   2. The exterior line which determines the form or magnitude
      of a body; outline; periphery. --Ray.
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   3. The act of limiting, or the state of being limited, by
      conditions or restraints; bound; confinement; limit.
      [1913 Webster]

            The circumscriptions of terrestrial nature.
                                                  --Johnson.
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            I would not my unhoused, free condition
            Put into circumscription and confine. --Shak.
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WordNet (r) 3.0 (2006):

circumscription
    n 1: the act of circumscribing