pantry vs still room

pantry and still room both are nouns.

Word	Noun	Adjective	Verb	Adverb
pantry	Yes	No	No	No
still room	Yes	No	No	No

As nouns, still room is a hyponym of pantry; that is, still room is a word with a more specific, narrower meaning than pantry:

pantry: a small storeroom for storing foods or wines
still room: a pantry or storeroom connected with the kitchen (especially in a large house) for preparing tea and beverages and for storing liquors and preserves and tea etc

Other hyponyms of pantry include stillroom.

pantry (noun)	still room (noun)
a small storeroom for storing foods or wines	a pantry or storeroom connected with the kitchen (especially in a large house) for preparing tea and beverages and for storing liquors and preserves and tea etc