from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. A group of three.
  • n. Music A chord of three tones, especially one built on a given root tone plus a major or minor third and a perfect fifth.
  • n. A section of a Pindaric ode consisting of the strophe, antistrophe, and epode.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A grouping of three.
  • n. A chord consisting of a root tone, the tone two degrees higher, and the tone four degrees higher in a given scale.
  • n. on a CRT display, a group of three neighbouring phosphor dots, coloured green, red, and blue.
  • n. A branch of a Chinese underground criminal society, mostly based in Hong Kong.

from the GNU version of the Collaborative International Dictionary of English

  • n. A union of three; three objects treated as one; a ternary; a trinity.
  • n.
  • n. A chord of three notes.
  • n. The common chord, consisting of a tone with its third and fifth, with or without the octave.
  • n. An element or radical whose valence is three.

from The Century Dictionary and Cyclopedia

  • n. plural See the Triad Society.
  • n. A union or conjunction of three; a group or class of three persons or things closely related; a trinity.
  • n. In chem., an element or radical which will combine with three atoms of a monad element or radical; a trivalent element or radical.
  • n. In music, a chord of three tones, including a given tone with its major or minor third and its perfect, augmented, or diminished fifth. A triad is named from the given tone or root: as, triad of G; dominant triad. See chord, 4. Also trias.
  • n. In Welsh lit., a form of composition characterized by the arrangement of the contents in groups of three.
  • n. In mythology, an intimate association of three kindred or correlated deities, sometimes considered as having the relationship of father, mother, and child, and forming a characteristic conception in some religious systems, as that of ancient Egypt.
  • n. In morphology, a tertiary unit of organization resulting; from integration of an aggregate of dyads. See dyad, 3.
  • n. An indeterminate product of three vectors.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. three people considered as a unit
  • n. a three-note major or minor chord; a note and its third and fifth tones
  • n. a set of three similar things considered as a unit
  • n. the cardinal number that is the sum of one and one and one


Late Latin trias, triad-, from Greek, the number three; see trei- in Indo-European roots.
(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin triad-, stem of trias ("three, triad"), from Ancient Greek τριάς (trias); applied by British authorities to underground society in Hong Kong based on geometry of Chinese character. (Wiktionary)


  • Thus _e. g._, the large I shows that the triad on the first tone (in major) is a _major triad_, the small II shows that the triad on the second tone is minor, etc.

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  • Rienhoff is still in the midst of this project, which he dubbed his triad transcriptome experiment—the "triad" consisting of mother, father, and offspring.

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  • Completing the triad is the intimate Transit Lounge (141 Tai An Road; 86-21-6283-3051), a favorite among Japanese men who come for the swanky red banquettes, loungey vibe and mojitos.

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  • The old tradition found its way to India (if the Hindus did not borrow the idea from the Greeks); and one of the forms of Mahadeva, the third person of their triad, is entitled “Ardhanárí” = the

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  • I believe that, like the horse-bird-muffin triad, one is not necessarily just a dork, nerd, or geek.

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  • This triad is responsible for the profits you're enjoying right now.

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  • Fortunately, it’s not a long or complicated manual: Nearly every part of a dog’s behavior can be described by employing three concepts I call the triad: instinct versus choice, the seven basic needs, and pain versus pleasure.

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  • Burke was there for the birth of the so-called triad, the three-sided nuclear force—missiles, manned bombers, and submarines—the U.S. was embarked upon building.

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  • How reward power is distributed in the triad has been the focus of experiments regarding the bargaining process.

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  • 1546 St. Papers Hen. VIII, XI. 341 Two thynges I noted in thEmperour, diligent herynge of me, and good wordys; yf deadis shal nowe folowe accordingely, the triade shall be perfecte.

    May 20, 2008