quartern vs twenty-five percent

quartern and twenty-five percent both are nouns.

Word	Noun	Adjective	Verb	Adverb
quartern	Yes	No	No	No
twenty-five percent	Yes	No	No	No

As nouns, quartern and twenty-five percent are synonyms defined as:

Other synonyms of quartern include fourth, fourth part, one-fourth, one-quarter, quarter.

quartern (noun)	twenty-five percent (noun)
one of four equal parts	one of four equal parts