Meaning of quaternary

Definition of quaternary

(adj) consisting of or especially arranged in sets of four; "quaternate leaves"; "a quaternary compound"
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"
(noun) last 2 million years
the cardinal number that is the sum of three and one

Other information on quaternary

WIKIPEDIA results for quaternary
Amazon results for quaternary