exhaustion vs inanition

exhaustion and inanition both are nouns.

Word	Noun	Adjective	Verb	Adverb
exhaustion	Yes	No	No	No
inanition	Yes	No	No	No

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

Other hyponyms of exhaustion include frazzle, brain-fag, mental exhaustion.

exhaustion (noun)	inanition (noun)
the act of exhausting something entirely	exhaustion resulting from lack of food
serious weakening and loss of energy	weakness characterized by a lack of vitality or energy
extreme fatigue