Definitions
1.NounA group or set of four; a foursome, a quartet.
2.NounA group or set of four; a foursome, a quartet.
3.NounA group of four persons forming the Godhead, in contrast to the Trinity comprising three persons.
4.NounSynonym of quarter (“a fourth part”).
5.NounSynonym of fourness (“the property or state of being four in number”).