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.
      [1913 Webster]

   2. The exterior line which determines the form or magnitude
      of a body; outline; periphery. --Ray.
      [1913 Webster]

   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.
      [1913 Webster]

            I would not my unhoused, free condition
            Put into circumscription and confine. --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

circumscription
    n 1: the act of circumscribing

Moby Thesaurus II by Grady Ward, 1.0:

164 Moby Thesaurus words for "circumscription":
   abbreviation, allowance, astriction, astringency, ban, bar,
   barring, beleaguerment, besetment, blockade, blockading,
   border line, bottleneck, bound, boundaries, boundary,
   boundary condition, boundary line, bounds, bourn, bourns, boycott,
   break boundary, breakoff point, ceiling, cervix, cession,
   circumference, coarctation, compactedness, compaction, compass,
   compression, compressure, concentration, concession, condensation,
   confine, confinement, confines, consolidation, constriction,
   constringency, contraction, contracture, coordinates, cordoning,
   cramp, cramping, curtailment, cutoff, cutoff point, deadline,
   debarment, debarring, decrease, delimitation, demarcation,
   determinant, diminuendo, division line, edges, embargo, enclosure,
   end, envelopment, exception, exclusion, exemption,
   extenuating circumstances, extremity, finish, floor, fringes,
   frontier, grain of salt, grant, hedge, hedging, high-water mark,
   hourglass, hourglass figure, immurement, imprisonment,
   inadmissibility, incarceration, inclusion, injunction, interface,
   isthmus, knitting, limen, limit, limitation, limitations,
   limiting factor, limits, line, line of demarcation, lockout,
   low-water mark, lower limit, march, marches, mark,
   mental reservation, mete, metes, metes and bounds, modification,
   narrow place, narrowing, neck, nonadmission, omission, outlines,
   outskirts, pale, parameters, perimeter, periphery, preclusion,
   prohibition, puckering, pursing, qualification, quarantine,
   reduction, rejection, relegation, repudiation, reservation,
   restraint, restriction, salvo, shortening, siege, skirts,
   solidification, special case, special treatment, specialness,
   specification, start, starting line, starting point, stint,
   stranglement, strangulation, striction, stricture, systole, taboo,
   target date, term, terminal date, terminus, threshold,
   time allotment, upper limit, verges, waiver, wasp waist,
   wrinkling