The Collaborative International Dictionary
octochord
Octachord \Oc"ta*chord\, n. [Gr. ? with eight strings; 'okta- (for 'oktw` eight) + ? string, chord: cf. F. octacorde.] (Mus.) An instrument of eight strings; a system of eight tones.
Wiktionary
octochord
n. (alternative form of octachord English)