building vs cornerstone

building and cornerstone both are nouns.

Word	Noun	Adjective	Verb	Adverb
building	Yes	No	No	No
cornerstone	Yes	No	No	No

building (noun)	cornerstone (noun)
the act of constructing something	a stone at the outer corner of two intersecting masonry walls
the commercial activity involved in repairing old structures or constructing new ones	a stone in the exterior of a large and important building; usually carved with a date and laid with appropriate ceremonies
a structure that has a roof and walls and stands more or less permanently in one place	the fundamental assumptions from which something is begun or developed or calculated or explained
the occupants of a building