Chord

Etymology

A genuinely tangled word: it began as a shortening of "accord" (agreement, concord), so it first meant a concord of notes. Its spelling was later reshaped to "chord" by association with Greek "chordē" (a string or gut of an instrument) — the same source as the anatomical "cord." So the harmonic word and the string word merged in spelling despite separate origins.

noun · /KORD/
Three or more notes sounded together as a single harmonic unit.
What it names
The basic building block of harmony — the handful of notes struck at once that gives a passage its color and mood.
Example
One minor chord under the last line, and the cheerful song suddenly sounded like a warning.
Related idea
A chord is notes stacked at one moment; an arpeggio is those same notes played one after another instead of together. The chord is the block; the arpeggio spreads it out in time.
noun · /KORD/
In geometry, a straight line joining two points on a curve.
What it names
the segment cutting across a circle or arc.
Example
A diameter is the longest chord of a circle.
Related idea
Same root as the musical chord — both from Greek "khordē," a string stretched taut.
noun · /KORD/
In the phrase “strike a chord,” an emotional response of recognition or sympathy.
What it names
the feeling of being resonated with.
Example
Her speech struck a chord with parents.
Related idea
Draws on the musical chord — something that sets the listener vibrating in sympathy.