incursion vs onrush

incursion and onrush both are nouns.

Word	Noun	Adjective	Verb	Adverb
incursion	Yes	No	No	No
onrush	Yes	No	No	No

As nouns, onrush is a hypernym of incursion; that is, onrush is a word with a broader meaning than incursion:

Other hypernyms of incursion include attack, onset, onslaught.

incursion (noun)	onrush (noun)
an attack that penetrates into enemy territory	(military) an offensive against an enemy (using weapons)
the act of entering some territory or domain (often in large numbers)	a forceful forward rush or flow
the mistake of incurring liability or blame