triad

noun

1. the cardinal number that is the sum of one and one and one

   noun.quantity

   Synonyms 3 deuce-ace iii leash tercet ternary ternion terzetto three threesome tierce trey trine trinity trio triplet troika

   Source: WordNet 3.0

2. a set of three similar things considered as a unit

   noun.group

   Synonyms trio triple triplet

   Source: WordNet 3.0

3. three people considered as a unit

   noun.group

   Synonyms threesome trinity trio

   Source: WordNet 3.0

4. a three-note major or minor chord; a note and its third and fifth tones

   noun.communication

   Synonyms common chord

   Source: WordNet 3.0

5. A union of three; three objects treated as one; a ternary; a trinity; as, a <i>triad</i> of deities.

   noun

   Source: webster1913