infinity \infin"ity\, n.; pl. infinities. l. infinitas;
   pref. in- not + finis boundary, limit, end: cf. f.
   infinit'e. see finite.
   1913 webster
   1. unlimited extent of time, space, or quantity; eternity;
      boundlessness; immensity. --sir t. more.
      1913 webster

            there can not be more infinities than one; for one
            of them would limit the other.        --sir w.
                                                  raleigh.
      1913 webster

   2. unlimited capacity, energy, excellence, or knowledge; as,
      the infinity of god and his perfections. --hooker.
      1913 webster

   3. endless or indefinite number; great multitude; as an
      infinity of beauties. --broome.
      1913 webster

   4. math. a quantity greater than any assignable quantity of
      the same kind.
      1913 webster

   note: mathematically considered, infinity is always a limit
         of a variable quantity, resulting from a particular
         supposition made upon the varying element which enters
         it. --davies  peck math. dict..
         1913 webster

   5. geom. that part of a line, or of a plane, or of space,
      which is infinitely distant. in modern geometry, parallel
      lines or planes are sometimes treated as lines or planes
      meeting at infinity.
      1913 webster

   circle at infinity, an imaginary circle at infinity,
      through which, in geometry of three dimensions, every
      sphere is imagined to pass.

   circular points at infinity. see under circular.
      1913 webster
see also:
infinities finite circle at infinity circular points at infinity circular 

circular \cir"cular\, a. l. circularis, fr. circulus circle:
   cf. f. circulaire. see circle.
   1913 webster
   1. in the form of, or bounded by, a circle; round.
      1913 webster

   2. repeating itself; ending in itself; reverting to the point
      of beginning; hence, illogical; inconclusive; as, circular
      reasoning.
      1913 webster

   3. adhering to a fixed circle of legends; cyclic; hence,
      mean; inferior. see cyclic poets, under cyclic.
      1913 webster

            had virgil been a circular poet, and closely adhered
            to history, how could the romans have had dido?
                                                  --dennis.
      1913 webster

   4. addressed to a circle, or to a number of persons having a
      common interest; circulated, or intended for circulation;
      as, a circular letter.
      1913 webster

            a proclamation of henry iii., . . . doubtless
            circular throughout england.          --hallam.
      1913 webster

   5. perfect; complete. obs.
      1913 webster

            a man so absolute and circular
            in all those wished-for rarities that may take
            a virgin captive.                     --massinger.
      1913 webster

   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 360deg.

   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.
      1913 webster
see also:
circle cyclic poets cyclic circular are circular cubics circular functions 
function circular instruments circular lines circular note  or circular letter 
credit circular numbers circular points at infinity circular polarization polarization 
circular sailing globular sailing circular saw saw