quaternary meaning and definition

QUATERNARY noun

Definition of Quaternary (noun)

1. last 2 million years
   • synonyms: Age of Man, Quaternary period
2. the cardinal number that is the sum of three and one
   • synonyms: 4, four, foursome, IV, Little Joe, quadruplet, quartet, quatern, quaternion, quaternity, tetrad

QUATERNARY adjective

Definition of quaternary (adjective)

1. consisting of or especially arranged in sets of four
   • "quaternate leaves"; "a quaternary compound"
   • synonyms: quaternate
2. coming next after the third and just before the fifth in position or time or degree or magnitude
   • "the quaternary period of geologic time extends from the end of the tertiary period to the present"
   • synonyms: 4th, fourth