Quaternary
[kwə'tɜːn(ə)rɪ] or [kwə'tɝnəri]
Definition
(a.) Consisting of four; by fours, or in sets of four.
(a.) Later than, or subsequent to, the Tertiary; Post-tertiary; as, the Quaternary age, or Age of man.
(n.) The number four.
(n.) The Quaternary age, era, or formation. See the Chart of Geology.
Inputed by Deborah
Definition
adj. consisting of four: by fours: pertaining to strata more recent than the Upper Tertiary: (math.) containing four variables.—n. a group of four things.—adjs. Quāt′ern Quāter′nāte composed of or arranged in sets of four.—n. Quāter′nion a set or group of four: a word of four syllables: (pl.) in mathematics a calculus of peculiar power and generality invented by Sir W. R. Hamilton of Dublin as a geometry primarily concerning itself with the operations by which one directed quantity or vector is changed into another.—v.t. to divide into quaternions: (Milt.) to divide into companies.—ns. Quāter′nionist a student of quaternions; Quātern′ity the state of being four a group of four.—Quaternary number ten; so called by the Pythagoreans because equal to 1 + 2 + 3 + 4.
Edited by Cary