n. The condition of being three; threeness.n. A set or group of three; a triad; a trio; a trine.n. [capitalized] The union of three persons—Father, Son, and Holy Spirit—in one Godhead; the threefold personality of the one divine being.n. A symbolical representation of the mystery of the Trinity, frequent in Christian art.n. In heraldry, a bearing compounded of an orle, a pall, and four roundels, three at the angles of the orle where the bands of the pall meet it, the fourth at the intersection of the bands of the pall.