Gehenna vs infernal region

Gehenna and infernal region both are nouns.

Word	Noun	Adjective	Verb	Adverb
Gehenna	Yes	No	No	No
infernal region	Yes	No	No	No

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

Gehenna: a place where the wicked are punished after death
infernal region: (Christianity) the abode of Satan and the forces of evil; where sinners suffer eternal punishment

Other hypernyms of Gehenna include Hell, Inferno, nether region, perdition, pit.

Gehenna (noun)	infernal region (noun)
a place where the wicked are punished after death	(Christianity) the abode of Satan and the forces of evil; where sinners suffer eternal punishment
	(religion) the world of the dead