Quaternary

·noun The number four.

II. Quaternary ·adj Consisting of four; by fours, or in sets of four.

III. Quaternary ·noun The Quaternary age, era, or formation. ·see the Chart of Geology.

IV. Quaternary ·adj Later than, or subsequent to, the Tertiary; Post-tertiary; as, the Quaternary age, or Age of man.