tomorrow vs hereafter

tomorrow and hereafter both are nouns.

Word	Noun	Adjective	Verb	Adverb
tomorrow	Yes	No	No	Yes
hereafter	Yes	No	No	Yes

As nouns, hereafter is a hypernym of tomorrow; that is, hereafter is a word with a broader meaning than tomorrow:

Other hypernyms of tomorrow include future, futurity, time to come.

tomorrow (noun)	hereafter (noun)
the near future	the time yet to come
the day after today	life after death

tomorrow (adverb)	hereafter (adverb)
the next day, the day after, following the present day	in a subsequent part of this document or statement or matter etc.
	following this in time or order or place; after this
	in a future life or state