The Collaborative International Dictionary of English v.0.48:

Saw \Saw\, n. [OE. sawe, AS. sage; akin to D. zaag, G. s[aum]ge,
   OHG. sega, saga, Dan. sav, Sw. s[*a]g, Icel. s["o]g, L.
   secare to cut, securis ax, secula sickle. Cf. Scythe,
   Sickle, Section, Sedge.]
   An instrument for cutting or dividing substances, as wood,
   iron, etc., consisting of a thin blade, or plate, of steel,
   with a series of sharp teeth on the edge, which remove
   successive portions of the material by cutting and tearing.
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   Note: Saw is frequently used adjectively, or as the first
         part of a compound.
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   Band saw, Crosscut saw, etc. See under Band,
      Crosscut, etc.

   Circular saw, a disk of steel with saw teeth upon its
      periphery, and revolved on an arbor.

   Saw bench, a bench or table with a flat top for for sawing,
      especially with a circular saw which projects above the
      table.

   Saw file, a three-cornered file, such as is used for
      sharpening saw teeth.

   Saw frame, the frame or sash in a sawmill, in which the
      saw, or gang of saws, is held.

   Saw gate, a saw frame.

   Saw gin, the form of cotton gin invented by Eli Whitney, in
      which the cotton fibers are drawn, by the teeth of a set
      of revolving circular saws, through a wire grating which
      is too fine for the seeds to pass.

   Saw grass (Bot.), any one of certain cyperaceous plants
      having the edges of the leaves set with minute sharp
      teeth, especially the Cladium Mariscus of Europe, and
      the Cladium effusum of the Southern United States. Cf.
      Razor grass, under Razor.

   Saw log, a log of suitable size for sawing into lumber.

   Saw mandrel, a mandrel on which a circular saw is fastened
      for running.

   Saw pit, a pit over which timbor is sawed by two men, one
      standing below the timber and the other above. --Mortimer.

   Saw sharpener (Zool.), the great titmouse; -- so named from
      its harsh call note. [Prov. Eng.]

   Saw whetter (Zool.), the marsh titmouse (Parus
      palustris); -- so named from its call note. [Prov. Eng.]


   Scroll saw, a ribbon of steel with saw teeth upon one edge,
      stretched in a frame and adapted for sawing curved
      outlines; also, a machine in which such a saw is worked by
      foot or power.
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The Collaborative International Dictionary of English v.0.48:

Circular \Cir"cu*lar\, a. [L. circularis, fr. circulus circle:
   cf. F. circulaire. See Circle.]
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   1. In the form of, or bounded by, a circle; round.
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   2. repeating itself; ending in itself; reverting to the point
      of beginning; hence, illogical; inconclusive; as, circular
      reasoning.
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   3. Adhering to a fixed circle of legends; cyclic; hence,
      mean; inferior. See Cyclic poets, under Cyclic.
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            Had Virgil been a circular poet, and closely adhered
            to history, how could the Romans have had Dido?
                                                  --Dennis.
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   4. Addressed to a circle, or to a number of persons having a
      common interest; circulated, or intended for circulation;
      as, a circular letter.
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            A proclamation of Henry III., . . . doubtless
            circular throughout England.          --Hallam.
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   5. Perfect; complete. [Obs.]
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            A man so absolute and circular
            In all those wished-for rarities that may take
            A virgin captive.                     --Massinger.
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   Circular are, any portion of the circumference of a circle.


   Circular cubics (Math.), curves of the third order which
      are imagined to pass through the two circular points at
      infinity.

   Circular functions. (Math.) See under Function.

   Circular instruments, mathematical instruments employed for
      measuring angles, in which the graduation extends round
      the whole circumference of a circle, or 360[deg].

   Circular lines, straight lines pertaining to the circle, as
      sines, tangents, secants, etc.

   Circular note or Circular letter.
      (a) (Com.) See under Credit.
      (b) (Diplomacy) A letter addressed in identical terms to a
          number of persons.

   Circular numbers (Arith.), those whose powers terminate in
      the same digits as the roots themselves; as 5 and 6, whose
      squares are 25 and 36. --Bailey. --Barlow.

   Circular points at infinity (Geom.), two imaginary points
      at infinite distance through which every circle in the
      plane is, in the theory of curves, imagined to pass.

   Circular polarization. (Min.) See under Polarization.

   Circular sailing or Globular sailing (Naut.), the method
      of sailing by the arc of a great circle.

   Circular saw. See under Saw.
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WordNet (r) 3.0 (2006):

circular saw
    n 1: a power saw that has a steel disk with cutting teeth on the
         periphery; rotates on a spindle [syn: circular saw, buzz
         saw]