Chord
in music, the simultaneous and harmonious union of different sounds, at first intuitively recognized by the ear, and afterward reduced to a science by the invention of the laws or rules of HARMONY (q. v.).
In geometry, a chord is the straight line which joins the two extremities of the arc of a curve. The chord of a circular arc is obtained by multiplying the radius by twice the sine of half the angle which the arc subtends at the center. nervous a