Triad or triade may refer to: a group of three. Humanities. Trichotomy (philosophy), often called triads. Triad (sociology), a group of three people as a unit of study. Triad (relationship), or ménage à trois. Music. Triad (music), chord consisting of root, third and fifth. Science and technology. Triad (anatomy), structure in skeletal muscles, formed by a T tubule surrounded by sarcoplasmic reticulum. Triad (computing), 3 bits of information storage. Triad (environmental science), management system for environmental cleanup.
https://en.wikipedia.org/wiki/Triad