[1] : The Collaborative International Dictionary of English v.0.48

curvature \cur"vature\ k?r"v?-t?r; 135, n. l. curvatura. see
   curvate.
   1. the act of curving, or the state of being bent or curved;
      a curving or bending, normal or abnormal, as of a line or
      surface from a rectilinear direction; a bend; a curve.
      --cowper.
      1913 webster

            the elegant curvature of their fronds. --darwin.
      1913 webster

   2. math. the amount of degree of bending of a mathematical
      curve, or the tendency at any point to depart from a
      tangent drawn to the curve at that point.
      1913 webster

   aberrancy of curvature geom., the deviation of a curve
      from a circular form.

   absolute curvature. see under absolute.

   angle of curvature geom., one that expresses the amount
      of curvature of a curve.

   chord of curvature. see under chord.

   circle of curvature. see osculating circle of a curve,
      under circle.

   curvature of the spine med., an abnormal curving of the
      spine, especially in a lateral direction.

   radius of curvature, the radius of the circle of curvature,
      or osculatory circle, at any point of a curve.
      1913 webster
see also:
curvate aberrancy of curvature absolute curvature absolute angle of curvature chord of curvature 
chord circle of curvature osculating circle of a curve circle curvature of the spine 
radius of curvature 

[2] : The Collaborative International Dictionary of English v.0.48

circle \cir"cle\ s~er"k'l, n. oe. cercle, f. cercle, fr. l.
   circulus whence also as. circul, dim. of circus circle,
   akin to gr. kri`kos, ki`rkos, circle, ring. cf. circus,
   circum-.
   1913 webster
   1. a plane figure, bounded by a single curve line called its
      circumference, every part of which is equally distant from
      a point within it, called the center.
      1913 webster

   2. the line that bounds such a figure; a circumference; a
      ring.
      1913 webster

   3. astron. an instrument of observation, the graduated limb
      of which consists of an entire circle.
      1913 webster

   note: when it is fixed to a wall in an observatory, it is
         called a mural circle; when mounted with a telescope
         on an axis and in y's, in the plane of the meridian, a
         meridian circle or transit circle; when involving
         the principle of reflection, like the sextant, a
         reflecting circle; and when that of repeating an
         angle several times continuously along the graduated
         limb, a repeating circle.
         1913 webster

   4. a round body; a sphere; an orb.
      1913 webster

            it is he that sitteth upon the circle of the earth.
                                                  --is. xi. 22.
      1913 webster

   5. compass; circuit; inclosure.
      1913 webster

            in the circle of this forest.         --shak.
      1913 webster

   6. a company assembled, or conceived to assemble, about a
      central point of interest, or bound by a common tie; a
      class or division of society; a coterie; a set.
      1913 webster

            as his name gradually became known, the circle of
            his acquaintance widened.             --macaulay.
      1913 webster

   7. a circular group of persons; a ring.
      1913 webster

   8. a series ending where it begins, and repeating itself.
      1913 webster

            thus in a circle runs the peasant's pain. --dryden.
      1913 webster

   9. logic a form of argument in which two or more unproved
      statements are used to prove each other; inconclusive
      reasoning.
      1913 webster

            that heavy bodies descend by gravity; and, again,
            that gravity is a quality whereby a heavy body
            descends, is an impertinent circle and teaches
            nothing.                              --glanvill.
      1913 webster

   10. indirect form of words; circumlocution. r.
       1913 webster

             has he given the lie,
             in circle, or oblique, or semicircle. --j.
                                                  fletcher.
       1913 webster

   11. a territorial division or district.
       1913 webster

   note:

   the circles of the holy roman empire, ten in number, were
      those principalities or provinces which had seats in the
      german diet.
      1913 webster

   azimuth circle. see under azimuth.

   circle of altitude astron., a circle parallel to the
      horizon, having its pole in the zenith; an almucantar.

   circle of curvature. see osculating circle of a curve
      below.

   circle of declination. see under declination.

   circle of latitude.
       a astron. a great circle perpendicular to the plane
           of the ecliptic, passing through its poles.
       b spherical projection a small circle of the sphere
           whose plane is perpendicular to the axis.

   circles of longitude, lesser circles parallel to the
      ecliptic, diminishing as they recede from it.

   circle of perpetual apparition, at any given place, the
      boundary of that space around the elevated pole, within
      which the stars never set. its distance from the pole is
      equal to the latitude of the place.

   circle of perpetual occultation, at any given place, the
      boundary of the space around the depressed pole, within
      which the stars never rise.

   circle of the sphere, a circle upon the surface of the
      sphere, called a great circle when its plane passes
      through the center of the sphere; in all other cases, a
      small circle.

   diurnal circle. see under diurnal.

   dress circle, a gallery in a theater, generally the one
      containing the prominent and more expensive seats.

   druidical circles eng. antiq., a popular name for certain
      ancient inclosures formed by rude stones circularly
      arranged, as at stonehenge, near salisbury.

   family circle, a gallery in a theater, usually one
      containing inexpensive seats.

   horary circles dialing, the lines on dials which show the
      hours.

   osculating circle of a curve geom., the circle which
      touches the curve at some point in the curve, and close to
      the point more nearly coincides with the curve than any
      other circle. this circle is used as a measure of the
      curvature of the curve at the point, and hence is called
      circle of curvature.

   pitch circle. see under pitch.

   vertical circle, an azimuth circle.

   voltaic circuit or voltaic circle. see under circuit.
      

   to square the circle. see under square.

   syn: ring; circlet; compass; circuit; inclosure.
        1913 webster
see also:
circus circum- mural circle meridian circle transit circle reflecting circle 
repeating circle the circles of the holy roman empire azimuth circle azimuth circle of altitude 
circle of curvature osculating circle of a curve circle of declination declination circle of latitude 
circles of longitude circle of perpetual apparition circle of perpetual occultation circle of the sphere diurnal circle 
diurnal dress circle druidical circles family circle horary circles 
pitch circle pitch vertical circle voltaic circuit voltaic circle 
circuit to square the circle square 

[3] : WordNet (r) 2.0

circle of curvature
     n : the circle that touches a curve on the concave side and
         whose radius is the radius of curvature syn: osculating
         circle
see also:
osculating circle 

Circle >> C Words
Circle, definition of term: Circle
circle_pag1.html

Curvature >> C Words
Curvature, definition of term: Curvature
curvature_pag1.html

Circle Round >> C Words
Circle Round, definition of term: Circle Round
circle+round_pag1.html

Traffic Circle >> T Words
Traffic Circle, definition of term: Traffic Circle
traffic+circle_pag1.html

Vicious Circle >> V Words
Vicious Circle, definition of term: Vicious Circle
vicious+circle_pag1.html

Pitch Circle >> P Words
Pitch Circle, definition of term: Pitch Circle
pitch+circle_pag1.html

Family Circle >> F Words
Family Circle, definition of term: Family Circle
family+circle_pag1.html

Arctic Circle >> A Words
Arctic Circle, definition of term: Arctic Circle
arctic+circle_pag1.html

Great Circle >> G Words
Great Circle, definition of term: Great Circle
great+circle_pag1.html