Definitions of Quaternary:
- noun: last 2 million years
- noun: the cardinal number that is the sum of three and one
- adjective: consisting of or especially arranged in sets of four
Example: "A quaternary compound"
- adjective: coming next after the third and just before the fifth in position or time or degree or magnitude
Example: "The quaternary period of geologic time extends from the end of the tertiary period to the present"
Search for Quaternary at other dictionaries: OneLook, Oxford, American Heritage, Merriam-Webster, Wikipedia