prison cell vs dungeon

prison cell and dungeon both are nouns.

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

As nouns, dungeon is a hyponym of prison cell; that is, dungeon is a word with a more specific, narrower meaning than prison cell:

Other hyponyms of prison cell include bullpen, detention cell, detention centre, cooler, tank, guardroom, hold, keep, sweatbox.

prison cell (noun)	dungeon (noun)
a room where a prisoner is kept	the main tower within the walls of a medieval castle or fortress
	a dark cell (usually underground) where prisoners can be confined