Qua*ter"na*ry , n. [L. numerus quaternarius: cf. F.
quaternaire.]
1. The number four.
Boyle.
2. (Geol.) The Quaternary age, era, or formation. See the Chart of Geology.
Qua*ter"na*ry (?), a.
[L. quaternarius consisting of four each,
containing four, fr. quaterni four each, fr. quattuor four: cf. F. quaternaire. See Four.]
1. Consisting of four; by fours, or in sets of four.
2. (Geol.)
Later than, or subsequent to, the Tertiary; Post-tertiary; as, the Quaternary age, or Age of man.
Hear it pronounced