1. [n]  an advertisement (usually printed on a page or in a leaflet) intended for wide distribution; "he mailed the circular to all subscribers"
2. [adj]  marked by or moving in a cycle
3. [adj]  having a circular shape
4. [adj]  shaped like a ring

CIRCULAR is a 8 letter word that starts with C.

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

2. \Cir"cu*lar\, n. [Cf. (for sense 1) F. circulaire,
   lettre circulaire. See {Circular}, a.]
   1. A circular letter, or paper, usually printed, copies of
      which are addressed or given to various persons; as, a
      business circular.
   
   2. A sleeveless cloak, cut in circular form.