“+...- noun
Etymology: Late Latin hypolyd ius hypolydian (from Greek hypolydios, from hypo- + lydios Lydian) + English -an; hypolydian mode, translation of Greek hypolydios tonos
1. : a Greek mode consisting of two disjunct tetrachords represented on the white keys of the piano by a descending diatonic scale from F to F — see greek mode illustration
2. : a plagal ecclesiastical mode consisting of a tetrachord and an upper conjunct pentachord represented on the white keys of the piano by an ascending diatonic scale from C to C — see mode illustration