tinea cruris vs tinea

tinea cruris and tinea both are nouns.

Word	Noun	Adjective	Verb	Adverb
tinea cruris	Yes	No	No	No
tinea	Yes	No	No	No

As nouns, tinea is a hypernym of tinea cruris; that is, tinea is a word with a broader meaning than tinea cruris:

tinea cruris: fungal infection of the groin (most common in men)
tinea: infections of the skin or nails caused by fungi and appearing as itching circular patches

Other hypernyms of tinea cruris include ringworm, roundworm.

tinea cruris (noun)	tinea (noun)
fungal infection of the groin (most common in men)	infections of the skin or nails caused by fungi and appearing as itching circular patches