tri·​ad | \ ˈtrī-ˌad also -əd How to pronounce triad (audio) \

Definition of triad

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

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Other Words from triad

triadic \ trī-​ˈa-​dik How to pronounce triadic (audio) \ adjective
triadically \ trī-​ˈa-​di-​k(ə-​)lē How to pronounce triadically (audio) \ adverb

Did You Know?

The best-known type of triad is a type of musical chord consisting of three notes. A D-major triad is made up of the notes D, F-sharp, and A; an F-minor triad is made up of F, A-flat, and C; and so on. Major and minor triads form the basis of tonal music, and songs and other pieces usually end with a triadic harmony. In medicine, a triad is a set of three symptoms that go together. The Chinese criminal organizations called triads got their name from the triangular symbol that they used back when they began, centuries ago, as patriotic organizations. Today, with over 100,000 members, the triads operate in the U.S., Canada, and many other countries.

Examples of triad in a Sentence

a triad of candlesticks on the mantle
Recent Examples on the Web Fourteen are Ohio-class ballistic missile submarines, part of America’s nuclear triad and built to carry out nuclear deterrence patrols. Kyle Mizokami, Popular Mechanics, "The U.S. Navy Signs Up for 9 New Nuclear Submarines," 3 Dec. 2019 The ballistic missile program’s recent troubles add to a laundry list of obstacles facing the nuclear triad recapitalization plan. Washington Post, "Air Force halts funding for Boeing’s ballistic missile replacement," 23 Oct. 2019 Others might form triads or quads — committed relationships among three or four people. Jason Silverstein, CBS News, ""Things are opening up": Non-monogamy is more common than you'd think," 27 Oct. 2019 The starry triad of Future, Post, and Halsey pose a threat to any potential Hot 100 contenders. Billboard Staff, Billboard, "Five Burning Questions: Billboard Staffers Discuss Post Malone's Massive First Week For 'Hollywood's Bleeding'," 17 Sep. 2019 As a teenager, Andrews fell into Hong Kong’s triad gangs, roaming the streets until he was arrested one day for stealing a cellphone. Los Angeles Times, "As China pushes in, Hong Kong’s first ethnic minority social worker wants a future for everyone," 23 Aug. 2019 Last Monday, police arrested six men in connection with the attack, including some linked to triad gangs. NBC News, "China blames Hong Kong violence on Western forces, defends police," 29 July 2019 Allegations of collusion between communists and Hong Kong’s triad gangs have a long history in the territory. The Economist, "Hong Kong’s violent protests against Chinese rule," 25 July 2019 Pro-China legislator Junius Ho was filmed shaking hands and thanking the triads for their hard work at the scene. The Economist, "Protesters are fighting for an open society," 20 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'triad.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of triad

1546, in the meaning defined at sense 1

History and Etymology for triad

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

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Time Traveler for triad

Time Traveler

The first known use of triad was in 1546

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Statistics for triad

Last Updated

15 Jan 2020

Cite this Entry

“Triad.” The Dictionary, Merriam-Webster Inc., Accessed 24 January 2020.

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More Definitions for triad


How to pronounce triad (audio)

English Language Learners Definition of triad

: a group of three usually related people or things
: a secret Chinese criminal organization


tri·​ad | \ ˈtrī-ˌad How to pronounce triad (audio) \

Kids Definition of triad

: a chord made up usually of the first, third, and fifth notes of a scale


tri·​ad | \ ˈtrī-ˌad also -əd \

Medical Definition of triad

1 : a union or group of three a triad of symptoms
2 : a trivalent element, atom, or radical

Other Words from triad

triadic \ trī-​ˈad-​ik How to pronounce triadic (audio) \ adjective

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More from Merriam-Webster on triad

Thesaurus: All synonyms and antonyms for triad

Rhyming Dictionary: Words that rhyme with triad

Spanish Central: Translation of triad

Nglish: Translation of triad for Spanish Speakers

Britannica English: Translation of triad for Arabic Speakers Encyclopedia article about triad

Comments on triad

What made you want to look up triad? Please tell us where you read or heard it (including the quote, if possible).


a feeling of well-being or elation

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