TRIAD

trio, threesome, triad, trinity

(noun) three people considered as a unit

trio, triad, triplet, triple

(noun) a set of three similar things considered as a unit

three, III, trio, threesome, tierce, leash, troika, triad, trine, trinity, ternary, ternion, triplet, tercet, terzetto, trey, deuce-ace

(noun) the cardinal number that is the sum of one and one and one

Source: WordNet® 3.1

Etymology

Noun

triad (plural triads)

A grouping of three.

Synonyms: threesome, trine, trinity, trio, triplet, troika, triumvirate, Thesaurus:trio

A word of three syllables.

Synonym: trisyllable

A branch of a Chinese underground criminal society, mostly based in Hong Kong.

(electronics) on a CRT display, a group of three neighbouring phosphor dots, coloured green, red, and blue.

(music) A chord consisting of a root tone, the tone two degrees higher, and the tone four degrees higher in a given scale.

Coordinate terms

• (group of three): monad · duad, dyad · triad · tetrad · pentad · hexad · heptad · octad · ennead, nonad · decad, decade · hendecad · dodecad, duodecade

• (word of four syllables): quaternion

Anagrams

• drait, iTard

Source: Wiktionary

Tri"ad, n. Etym: [L.trias, -adis, Gr. triade. See Three, and cf. Trias, Trio.]

1. A union of three; three objects treated as one; a ternary; a trinity; as, a triad of deities.

2. (Mus.) (a) A chord of three notes. (b) The common chord, consisting of a tone with its third and fifth, with or without the octave.

3. (Chem.)

Definition: An element or radical whose valence is three. Triads of the Welsh bards, poetical histories, in which the facts recorded are grouped by threes, three things or circumstances of a kind being mentioned together.

– Hindoo triad. See Trimurti.

Source: Webster’s Unabridged Dictionary 1913 Edition