prison cell vs room

prison cell and room both are nouns.

Word	Noun	Adjective	Verb	Adverb
prison cell	Yes	No	No	No
room	Yes	No	Yes	No

As nouns, room is a hypernym of prison cell; that is, room is a word with a broader meaning than prison cell:

prison cell (noun)	room (noun)
a room where a prisoner is kept	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

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