airport vs flying field

airport and flying field both are nouns.

Word	Noun	Adjective	Verb	Adverb
airport	Yes	No	No	No
flying field	Yes	No	No	No

As nouns, flying field is a hypernym of airport; that is, flying field is a word with a broader meaning than airport:

airport: an airfield equipped with control tower and hangars as well as accommodations for passengers and cargo
flying field: a place where planes take off and land

Other hypernyms of airport include airfield, field, landing field.

airport (noun)	flying field (noun)
an airfield equipped with control tower and hangars as well as accommodations for passengers and cargo	a place where planes take off and land