fly-by vs flying

fly-by and flying both are nouns.

Word	Noun	Adjective	Verb	Adverb
fly-by	Yes	No	No	No
flying	Yes	Yes	No	No

As nouns, flying is a hypernym of fly-by; that is, flying is a word with a broader meaning than fly-by:

fly-by: a flight at a low altitude (usually of military aircraft) over spectators on the ground
flying: an instance of traveling by air

Other hypernyms of fly-by include flight.

fly-by (noun)	flying (noun)
a flight at a low altitude (usually of military aircraft) over spectators on the ground	an instance of traveling by air

fly-by (adjective)	flying (adjective)
	hurried and brief
	moving swiftly