air hostess vs adult female

air hostess and adult female both are nouns.

Word	Noun	Adjective	Verb	Adverb
air hostess	Yes	No	No	No
adult female	Yes	No	No	No

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

Other hypernyms of air hostess include flight attendant, steward, woman.

air hostess (noun)	adult female (noun)
a woman steward on an airplane	an adult female person (as opposed to a man)