bring forth vs birth

bring forth is not a noun while birth is a noun.

Word	Noun	Adjective	Verb	Adverb
bring forth	No	No	Yes	No
birth	Yes	No	Yes	No

As verbs, birth is a hyponym of bring forth; that is, birth is a word with a more specific, narrower meaning than bring forth:

Other hyponyms of bring forth include bear, deliver, give birth, have, sporulate, crank out, grind out, manufacture.

bring forth (noun)	birth (noun)
	the event of being born
	a baby born; an offspring
	the process of giving birth
	the kinship relation of an offspring to the parents
	the time when something begins (especially life)

bring forth (verb)	birth (verb)
make (offspring) by reproduction	cause to be born
bring forth or yield
produce, create
bring out for display