populate vs room

populate is not a noun while room is a noun.

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

As verbs, room is a hyponym of populate; that is, room is a word with a more specific, narrower meaning than populate:

populate (noun)	room (noun)
	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

populate (verb)	room (verb)
fill with inhabitants	live and take one's meals at or in
be an inhabitant of or reside in