onrush vs penetration

onrush and penetration both are nouns.

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

As nouns, penetration is a hyponym of onrush; that is, penetration is a word with a more specific, narrower meaning than onrush:

onrush (noun)	penetration (noun)
(military) an offensive against an enemy (using weapons)	an attack that penetrates into enemy territory
a forceful forward rush or flow	the act of entering into or through something
	the act (by a man) of inserting his penis into the vagina of a woman
	the depth to which something penetrates (especially the depth reached by a projectile that hits a target)
	the ability to make way into or through something
	clear or deep perception of a situation