1. (n.) A union of three persons or things\; three objects treated as one; a ternary; a trinity; as, a triad of deities.

2. (n.) A chord of three notes.

3. (n.) The common chord, consisting of a tone with its third and fifth, with or without the octave.

4. (n.) An element or radical whose valence is three.

arpeggio broken chord chord clover common chord concento concord consonant chord deuce-ace diminished seventh chord dominant chord enharmonic leash major triad minor chord set of three seventh chord shamrock sixth chord tercet ternary ternion terzetto three threesome tierce tonic triad trefoil trey trialogue triangle tricorn trident triennium trihedron trilogy trimester trine trinity trinomial trio triphthong triple triple crown triple threat triplet triplopy tripod triptych trireme triseme triskelion trisul triumvirate triune triunity trivet troika unbroken chord