Origin: Latin suffix -ary
Quaternary has 7 different meanings across 3 categories:
Noun · Adjective · Proper Noun
last 2 million years
the cardinal number that is the sum of three and one
A quaternary compound.
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"
Of fourth rank or order
The geological period of the Cenozoic Era immediately following the Tertiary. It is subdivided into the Pleistocene and the Holocene Epochs.