quaternity vs quaternary

quaternity and quaternary both are nouns.

Word	Noun	Adjective	Verb	Adverb
quaternity	Yes	No	No	No
quaternary	Yes	Yes	No	No

As nouns, quaternity and quaternary are synonyms defined as:

quaternity and quaternary: the cardinal number that is the sum of three and one

Other synonyms of quaternity include 4, four, foursome, IV, Little Joe, quadruplet, quartet, quatern, quaternion, tetrad.

quaternity (noun)	quaternary (noun)
the cardinal number that is the sum of three and one	the cardinal number that is the sum of three and one

quaternity (adjective)	quaternary (adjective)
	consisting of or especially arranged in sets of four
	coming next after the third and just before the fifth in position or time or degree or magnitude