enrolment vs ingress

enrolment and ingress both are nouns.

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

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

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

enrolment (noun)	ingress (noun)
the act of enrolling	the act of entering
	(astronomy) the disappearance of a celestial body prior to an eclipse