living room vs living-room

living room and living-room both are nouns.

Word	Noun	Adjective	Verb	Adverb
living room	Yes	No	No	No
living-room	Yes	No	No	No

As nouns, living room and living-room are synonyms defined as:

living room and living-room: a room in a private house or establishment where people can sit and talk and relax

Other synonyms of living room include front room, parlor, parlour, sitting room.

living room (noun)	living-room (noun)
a room in a private house or establishment where people can sit and talk and relax	a room in a private house or establishment where people can sit and talk and relax