chapterhouse vs frat house

chapterhouse and frat house both are nouns.

Word	Noun	Adjective	Verb	Adverb
chapterhouse	Yes	No	No	No
frat house	Yes	No	No	No

As nouns, chapterhouse and frat house are synonyms defined as:

chapterhouse and frat house: a house used as a residence by a chapter of a fraternity

Other synonyms of chapterhouse include fraternity house.

chapterhouse (noun)	frat house (noun)
a house used as a residence by a chapter of a fraternity	a house used as a residence by a chapter of a fraternity
a building attached to a monastery or cathedral; used as a meeting place for the chapter