billiard saloon vs billiard parlor

billiard saloon and billiard parlor both are nouns.

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

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

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

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

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