building vs rustication

building and rustication both are nouns.

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

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

building (noun)	rustication (noun)
the act of constructing something	the action of retiring to and living in the country
the commercial activity involved in repairing old structures or constructing new ones	banishment into the country
a structure that has a roof and walls and stands more or less permanently in one place	the construction of masonry or brickwork in a rustic manner
the occupants of a building	temporary dismissal of a student from a university
	the condition naturally attaching to life in the country