triad

1 of 2

noun

tri·​ad ˈtrī-ˌad 

also -əd

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

triadic

trī-ˈa-dik 

adjective

triadically

trī-ˈa-di-k(ə-)lē 

adverb

triadic

2 of 2

adjective

tri·​ad·​ic (ˈ)trī¦adik 

-dēk

: having the characteristics of or constituting a triad : consisting of or involving a triad

a triadic poem

The song's harmony is mostly triadic.

the triadic nature of color vision

—Medical Physics

an erudite triadic biography of Lenin, Trotsky, and Stalin

—R. A. Bauer

suggested the use of triadic definitions in which the verbal symbol is made responsible both to an object or field of objects and to a detailed description of the objects

—C. W. Shumaker

thus language involves what logicians call a triadic relation. There is the speaker, the thing said, and the one spoken to

—John Dewey

triadically

-də̇k(ə)lē 

-dēk-, 

-li

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.

Synonyms of triad

Noun

• trio
• trinity

Examples of triad in a Sentence

Noun

a triad of candlesticks on the mantel

Recent Examples on the Web

Noun

Beyond missiles and bombers The triad is more than launch platforms. —Kaif Shaikh, Interesting Engineering, 26 May 2026

The executive triad and Gervais’s team worked with CBS to find middle ground between the network method and the Love Island spirit. —Anna Peele, Vulture, 20 May 2026

Actor Bradley Gibson works triple time in separate eras, taking on a triad of multigenerational roles in the Pique family tale. —Christopher Smith, Oc Register, 9 May 2026

There would be a chord, a triad, then a bass note that wasn’t necessarily in that chord and then a melody that also wasn’t necessarily in the chord. —New York Times, 28 Apr. 2026

Word History

Etymology

Noun

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

First Known Use

Noun

1546, in the meaning defined at sense 1

Adjective

1788, in the meaning defined above

Rhymes for triad

• ad
• add
• bad
• brad
• cad
• clad
• dad
• fad
• gad
• glad
• grad
• had

Kids Definition

triad

noun

tri·​ad ˈtrī-ˌad 

also -əd

1

: a union or group of three usually closely related persons or things

2

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

triadic

trī-ˈad-ik 

adjective

Medical Definition

triad

noun

tri·​ad

ˈtrī-ˌad also -əd

1

: a union or group of three

a triad of symptoms

2

: a trivalent element, atom, or radical

triadic

trī-ˈad-ik 

adjective