penetration vs ingress

penetration and ingress both are nouns.

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

As nouns, ingress is a hypernym of penetration; that is, ingress is a word with a broader meaning than penetration:

Other hypernyms of penetration include entering, entrance, entry, incoming.

penetration (noun)	ingress (noun)
an attack that penetrates into enemy territory	the act of entering
the act of entering into or through something	(astronomy) the disappearance of a celestial body prior to an eclipse
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