quaternity Meaning, Definition & Usage

  1. noun the cardinal number that is the sum of three and one
    tetrad; quadruplet; foursome; Little Joe; IV; four; quaternion; quatern; quaternary; quartet; 4.

WordNet

Qua*ter"ni*ty noun
Etymology
LL.quaternitas, fr. L. quaterni four each: cf. F. quaternité.
Definitions
  1. The number four. Obs. Sir T. Browne.
  2. The union of four in one, as of four persons; -- analogous to the theological term trinity.

Webster 1913