egress vs pop out

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

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

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

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

egress (noun)	pop 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)	pop out (verb)
come out of	come out suddenly or forcefully
	exit briefly
	bulge outward
	appear suddenly or unexpectedly; happen unexpectedly