Chord (noun)

1. Three or more musical notes played or sung at the same time.
2. A combination of three or more notes played together on a musical instrument.

Origin:

From latin word "chorda" meaning "string" or "cord".

Examples:

1. He played a chord on the piano.
2. The guitar chord chart was hanging on the wall.
3. The song had a complex chord progression.
4. The singer hit a sour chord during the performance.
5. The band played a series of chords to start the song.