interior vs penetralium

interior and penetralium both are nouns.

Word	Noun	Adjective	Verb	Adverb
interior	Yes	Yes	No	No
penetralium	Yes	No	No	No

As nouns, penetralium is a hyponym of interior; that is, penetralium is a word with a more specific, narrower meaning than interior:

Other hyponyms of interior include midland, midst, thick.

interior (noun)	penetralium (noun)
the inner or enclosed surface of something	the innermost parts
the region that is inside of something

interior (adjective)	penetralium (adjective)
situated within or suitable for inside a building
inside the country
of or coming from the middle of a region or country
inside and toward a center
located inward