inside vs penetralium

inside and penetralium both are nouns.

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

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

Other hyponyms of inside include midland, midst, thick.

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

inside (adjective)	penetralium (adjective)
relating to or being on the side closer to the center or within a defined space
confined to an exclusive group
away from the outer edge
being or applying to the inside of a building

inside (adverb)	penetralium (adverb)
within a building
on the inside
in reality
with respect to private feelings