house of ill repute vs cathouse

house of ill repute and cathouse both are nouns.

Word	Noun	Adjective	Verb	Adverb
house of ill repute	Yes	No	No	No
cathouse	Yes	No	No	No

As nouns, house of ill repute and cathouse are synonyms defined as:

house of ill repute and cathouse: a building where prostitutes are available

Other synonyms of house of ill repute include bagnio, bawdyhouse, bordello, brothel, house of prostitution, sporting house, whorehouse.

house of ill repute (noun)	cathouse (noun)
a building where prostitutes are available	a building where prostitutes are available