overflight vs flying

overflight and flying both are nouns.

Word	Noun	Adjective	Verb	Adverb
overflight	Yes	No	No	No
flying	Yes	Yes	No	No

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

overflight: a flight by an aircraft over a particular area (especially over an area in foreign territory)
flying: an instance of traveling by air

Other hypernyms of overflight include flight.

overflight (noun)	flying (noun)
a flight by an aircraft over a particular area (especially over an area in foreign territory)	an instance of traveling by air

overflight (adjective)	flying (adjective)
	hurried and brief
	moving swiftly