twenty-five percent vs fourth part

twenty-five percent and fourth part both are nouns.

Word	Noun	Adjective	Verb	Adverb
twenty-five percent	Yes	No	No	No
fourth part	Yes	No	No	No

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

Other synonyms of twenty-five percent include fourth, one-fourth, one-quarter, quarter, quartern.

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