CORD (derived through the Fr. corde, from the Lat. chorda, Gr. χορδή, the string of a musical instrument), a length of twisted or woven strands, in thickness coming between a rope and a string, a smaller kind of rope (q.v.). From the use of such a cord for measuring, the word is applied to a quantity of cut wood, differing according to locality. The variant “chord,” which, in spelling, reverts to the original Latin, is used in particular senses, as, in physiology, for such cord-like structures as the vocal chords; in the case of the “umbilical cord,” the other spelling is usually retained. In mathematics a “chord” is a straight line joining any two points on the same curve, and, in music, the word is used of several musical notes sounded simultaneously and in harmony (q.v.). In this last sense, “chord” is properly a shortened form of “accord,” agreement, from Late Lat. accordare, and the spelling with h is due to a confusion.