ichneumon vs mongoose

ichneumon and mongoose both are nouns.

Word	Noun	Adjective	Verb	Adverb
ichneumon	Yes	No	No	No
mongoose	Yes	No	No	No

As nouns, mongoose is a hypernym of ichneumon; that is, mongoose is a word with a broader meaning than ichneumon:

ichneumon: northern African mongoose; in ancient times thought to devour crocodile eggs
mongoose: agile grizzled Old World viverrine; preys on snakes and rodents

ichneumon (noun)	mongoose (noun)
northern African mongoose; in ancient times thought to devour crocodile eggs	agile grizzled Old World viverrine; preys on snakes and rodents