These two words are often confused?and with good reason, for they are really three. There are two words spelled chord. One comes from the word accord and refers to a harmonious combination of three or more musical notes. The other is an alteration of cord, taking its spelling from Greek chorda, ?string, gut,? by way of Latin. A mathematical chord is a line segment that joins two points on a curve.    1
  Cord itself means ?a string or rope.? It has many extensions, as in an electrical cord and a cord of wood. When referring to anatomical structures, it can be spelled in general usage either as cord or chord (again by influence of Greek and Latin). Strict medical usage requires cord, however. Your doctor examines your spinal cord and vocal cords, never your chords.    2
  When something strikes a chord with you, it is actually a metaphorical string that is being struck and not a triad of musical notes. But many of us feel harmonic overtones anyway.    3