heptachord

[ hep-tuh-kawrd ]
/ ˈhɛp təˌkɔrd /

noun

a musical scale of seven notes.
an interval of a seventh.
an ancient Greek stringed instrument.

Origin of heptachord

From the Greek word heptáchordos, dating back to 1720–30. See hepta-, chord1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019