billiard saloon vs billiard parlour

billiard saloon and billiard parlour both are nouns.

Word	Noun	Adjective	Verb	Adverb
billiard saloon	Yes	No	No	No
billiard parlour	Yes	No	No	No

As nouns, billiard saloon and billiard parlour are synonyms defined as:

billiard saloon and billiard parlour: a room in which billiards is played

Other synonyms of billiard saloon include billiard hall, billiard parlor, billiard room.

billiard saloon (noun)	billiard parlour (noun)
a room in which billiards is played	a room in which billiards is played