HEPTACHORD
Etymology
Noun
heptachord (plural heptachords)
(music) A system of seven sounds.
(music) A lyre with seven chords.
(poetry) A composition sung to the sound of seven chords or tones.
Source: Wiktionary
Hep"ta*chord, n. Etym: [Gr. "epta`xordos seven-stringed; "epta` seven
+ xordh` chord: cf. F. heptacorde. See Seven, and Chord.]
1. (Anc. Mus.)
(a) A system of seven sounds.
(b) A lyre with seven chords.
2. (Anc. Poet.)
Definition: A composition sung to the sound of seven chords or tones. Moore
(Encyc. of Music).
Source: Webster’s Unabridged Dictionary 1913 Edition