air hostess vs steward

air hostess and steward both are nouns.

Word	Noun	Adjective	Verb	Adverb
air hostess	Yes	No	No	No
steward	Yes	No	No	No

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

Other hypernyms of air hostess include flight attendant, adult female, woman.

air hostess (noun)	steward (noun)
a woman steward on an airplane	someone who manages property or other affairs for someone else
	a union member who is elected to represent fellow workers in negotiating with management
	one having charge of buildings or grounds or animals
	an attendant on an airplane
	the ship's officer who is in charge of provisions and dining arrangements