flight attendant vs steward

flight attendant and steward both are nouns.

Word	Noun	Adjective	Verb	Adverb
flight attendant	Yes	No	No	No
steward	Yes	No	No	No

As nouns, flight attendant and steward are synonyms defined as:

flight attendant (noun)	steward (noun)
an attendant 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