room light vs room

room light and room both are nouns.

Word	Noun	Adjective	Verb	Adverb
room light	Yes	No	No	No
room	Yes	No	Yes	No

room light (noun)	room (noun)
light that provides general illumination for a room	an area within a building enclosed by walls and floor and ceiling
	the people who are present in a room
	space for movement
	opportunity for

room light (verb)	room (verb)
	live and take one's meals at or in