jungle hen vs jungle fowl

jungle hen and jungle fowl both are nouns.

Word	Noun	Adjective	Verb	Adverb
jungle hen	Yes	No	No	No
jungle fowl	Yes	No	No	No

As nouns, jungle fowl is a hypernym of jungle hen; that is, jungle fowl is a word with a broader meaning than jungle hen:

jungle hen: female jungle fowl
jungle fowl: small Asiatic wild bird; believed to be ancestral to domestic fowl

Other hypernyms of jungle hen include gallina.

jungle hen (noun)	jungle fowl (noun)
female jungle fowl	small Asiatic wild bird; believed to be ancestral to domestic fowl