Chord \Chord\, n. [L chorda a gut, a string made of a gut, Gr. ?. In the sense of a string or small rope, in general, it is written cord. See Cord.] 1. The string of a musical instrument. --Milton. 2. (Mus.) A combination of tones simultaneously performed, producing more or less perfect harmony, as, the common chord. 3. (Geom.) A right line uniting the extremities of the arc of a circle or curve. 4. (Anat.) A cord. See Cord, n., 4. 5. (Engin.) The upper or lower part of a truss, usually horizontal, resisting compression or tension. --Waddell. Accidental, Common, & Vocal chords. See under Accidental, Common, and Vocal. Chord of an arch. See Illust. of Arch. Chord of curvature, a chord drawn from any point of a curve, in the circle of curvature for that point. Scale of chords. See Scale.

Curvature \Cur"va*ture\ (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. The elegant curvature of their fronds. --Darwin. 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. 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.

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