egress vs fall out

egress is a noun but fall out is not a noun.

Word	Noun	Adjective	Verb	Adverb
egress	Yes	No	Yes	No
fall out	No	No	Yes	No

As verbs, fall out is a hyponym of egress; that is, fall out is a word with a more specific, narrower meaning than egress:

Other hyponyms of egress include pop out, radiate, leak, escape, fall, debouch, come out.

egress (noun)	fall out (noun)
the act of coming (or going) out; becoming apparent
(astronomy) the reappearance of a celestial body after an eclipse
the becoming visible

egress (verb)	fall out (verb)
come out of	come to pass
	have a breach in relations
	drop out
	leave (a barracks) in order to take a place in a military formation, or leave a military formation
	come as a logical consequence; follow logically