airfare vs fare

airfare and fare both are nouns.

Word	Noun	Adjective	Verb	Adverb
airfare	Yes	No	No	No
fare	Yes	No	Yes	No

As nouns, fare is a hypernym of airfare; that is, fare is a word with a broader meaning than airfare:

Other hypernyms of airfare include transportation.

airfare (noun)	fare (noun)
the fare charged for traveling by airplane	an agenda of things to do
	the food and drink that are regularly served or consumed
	a paying (taxi) passenger
	the sum charged for riding in a public conveyance

airfare (verb)	fare (verb)
	eat well
	proceed or get along