(kôrd) noun Music
A combination of three or more tones sounded together according to the laws of harmony. The most important chords are the common chord, consisting of a fundamental tone with its major or minor third and its perfect fifth, and the chord of the seventh, called the dominant seventh.
—v.i. To be in harmony or accord. ◆ Homophone: cord. [Earlier cord, short for ACCORD; form infl. by CHORD²]
CHORD
cb and ab are chords.

(kôrd) noun
1. A string or cord of a musical instrument; hence, emotional response or reaction.
2. Geom. A straight line connecting the extremities of an arc; a secant; the portion of a straight line contained by its intersections with a curve.
3. Eng. One of the principal members of a bridge truss, horizontal or inclined.
4. Anat. A tendon, a connective ligament.
5. Aeron. The length of an airplane. ◆ Homophone: cord. [<L chorda <Gk. chordē string of a musical instrument. Doublet of CORD.]
—chord′al adjective