Quaternary
Quaternary , adjective
[Latin quaternarius consisting of four each, containing four, from quaterni four each, from quattuor four: compare French quaternaire. See Four.]
1.
Consisting of four; by fours, or in sets of four.
2.
(Geology) Later than, or subsequent to, the Tertiary; Post-tertiary; as, the Quaternary age, or Age of man.
Quaternary , noun
[Latin numerus quaternarius: compare French quaternaire.]
1.
The number four. — Boyle
2.
(Geology) The Quaternary age, era, or formation. See the Chart of Geology.