1. [Noun]: the cardinal number that is the sum of three and one

2. [Noun]: last 2 million years

3. 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"

4. consisting of or especially arranged in sets of four; "quaternate leaves"; "a quaternary compound"

Similar words to 'quaternary'

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