quaternity

Etymology
, from, from.

Noun

 * 1)  A group or set of four.
 * 2)  The state of being four.

Synonyms

 * , ; see also Thesaurus:quartet
 * ; see also Thesaurus:fourness

Related terms

 * quaternary
 * unity (oneness)
 * duality (twoness)
 * trinity (threeness)
 * quinity (fiveness)