tri·​ad | \ˈtrī-ˌad also -əd \

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 \ adjective
triadically \trī-​ˈa-​di-​k(ə-​)lē \ 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

More than any other arm of the triad, missile submarines deter war by ensuring a revenge attack is possible. Kyle Mizokami, Popular Mechanics, "The U.S. Navy's Next Missile Sub Is Called USS Columbia," 15 Dec. 2016 That same showrunner also wanted me to feature Chinese triads, have them use Japanese throwing stars, and get into a kung-fu fight with our (white) lead. Adele Lim, Glamour, "Crazy Rich Asians Is the Love Letter to My People I Never Had a Chance to Write," 17 Aug. 2018 And the land leg of the US nuclear triad, the Minuteman III ICBM, entered service in the 1960s. Sean Gallagher, Ars Technica, "Sitrep: The Air Force’s senior-citizen chopper may have to hold off retirement," 31 July 2018 Their only reference point seems to be the mutual antagonism between their respective father figures, a steely police superintendent (Anthony Wong) and a scheming triad boss (Eric Tsang). Patrick Friel, Chicago Reader, "Crime / Film / Foreign / On Video / Television / The Internet Undercover cops infiltrate FilmStruck this week," 10 Apr. 2018 For evidence, take a closer look at last night's triad of side-butt devotees. Lauren Valenti, Marie Claire, "It's Official: Side-Butt Is the New Side-Boob," 31 Aug. 2015 The variety of quality trails is the result of a triad of a blank slate, plentiful financial resources and supportive city officials. Joe Jackson,, "Redding is California’s secret mountain biking mecca," 8 June 2018 Undersea strategic deterrence therefore, as described by Navy leaders, brings a critical element of the nuclear triad by ensuring a second strike ability in the event of attack. Kris Osborn, Fox News, "Navy mulls acceleration of first nuclear-armed Columbia ballistic missile sub," 30 May 2018 At the height of the American century decades ago, government, companies and universities acted as a triad for innovation. Zachary Karabell, WIRED, "Why Trump's Misguided China Tariffs Won't Help the US," 31 Mar. 2018

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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Statistics for triad

Last Updated

3 Dec 2018

Look-up Popularity

Time Traveler for triad

The first known use of triad was in 1546

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More Definitions for triad



English Language Learners Definition of triad

: a group of three usually related people or things

: a secret Chinese criminal organization


tri·​ad | \ˈtrī-ˌad \

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 \ adjective

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More from Merriam-Webster on triad

Rhyming Dictionary: Words that rhyme with triad

Thesaurus: All synonyms and antonyms for 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 nest or breeding place

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