house of ill repute vs brothel

house of ill repute and brothel both are nouns.

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

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

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

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

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