region vs nirvana

region and nirvana both are nouns.

Word	Noun	Adjective	Verb	Adverb
region	Yes	No	No	No
nirvana	Yes	No	No	No

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

region (noun)	nirvana (noun)
a part of an animal that has a special function or is supplied by a given artery or nerve	any place of complete bliss and delight and peace
a knowledge domain that you are interested in or are communicating about	(Hinduism and Buddhism) the beatitude that transcends the cycle of reincarnation; characterized by the extinction of desire and suffering and individual consciousness
the extended spatial location of something
a large indefinite location on the surface of the Earth
the approximate amount of something (usually used prepositionally as in `in the region of')