billiard parlour vs billiard saloon

billiard parlour and billiard saloon both are nouns.

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

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

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

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

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