snake pit vs region

snake pit and region both are nouns.

Word	Noun	Adjective	Verb	Adverb
snake pit	Yes	No	No	No
region	Yes	No	No	No

As nouns, region is a hypernym of snake pit; that is, region is a word with a broader meaning than snake pit:

Other hypernyms of snake pit include part.

snake pit (noun)	region (noun)
pejorative terms for an insane asylum	a part of an animal that has a special function or is supplied by a given artery or nerve
any place of pain and turmoil	a knowledge domain that you are interested in or are communicating about
	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')