dining-room vs mess

dining-room and mess both are nouns.

Word	Noun	Adjective	Verb	Adverb
dining-room	Yes	No	No	No
mess	Yes	No	Yes	No

As nouns, mess is a hyponym of dining-room; that is, mess is a word with a more specific, narrower meaning than dining-room:

Other hyponyms of dining-room include dining-hall, mess hall, triclinium.

dining-room (noun)	mess (noun)
a room used for dining	a (large) military dining room where service personnel eat or relax
	a meal eaten in a mess hall by service personnel
	soft semiliquid food
	(often followed by `of') a large number or amount or extent
	a state of confusion and disorderliness
	informal terms for a difficult situation

dining-room (verb)	mess (verb)
	make a mess of or create disorder in
	eat in a mess hall