Main Entry: tri·ad

Pronunciation: \ˈtrī-ˌad also -əd\

Function: noun

Etymology: Latin triad-, trias, from Greek, from treis three

Date: 1546

1 : a union or group of three : trinity
2 : a chord of three tones consisting of a root with its third and fifth and constituting the harmonic basis of tonal music

— tri·ad·ic \trī-ˈa-dik\ adjective

— tri·ad·i·cal·ly \-di-k(ə-)lē\ adverb