tribade vs adult female

tribade and adult female both are nouns.

Word	Noun	Adjective	Verb	Adverb
tribade	Yes	No	No	No
adult female	Yes	No	No	No

As nouns, adult female is a hypernym of tribade; that is, adult female is a word with a broader meaning than tribade:

Other hypernyms of tribade include gay, homo, homophile, homosexual, woman.

tribade (noun)	adult female (noun)
a female homosexual	an adult female person (as opposed to a man)