athlete's foot vs tinea

athlete's foot and tinea both are nouns.

Word	Noun	Adjective	Verb	Adverb
athlete's foot	Yes	No	No	No
tinea	Yes	No	No	No

As nouns, tinea is a hypernym of athlete's foot; that is, tinea is a word with a broader meaning than athlete's foot:

athlete's foot: fungal infection of the feet
tinea: infections of the skin or nails caused by fungi and appearing as itching circular patches

Other hypernyms of athlete's foot include ringworm, roundworm.

athlete's foot (noun)	tinea (noun)
fungal infection of the feet	infections of the skin or nails caused by fungi and appearing as itching circular patches