bombproof vs invulnerable

bombproof is a noun but invulnerable is not a noun.

Word	Noun	Adjective	Verb	Adverb
bombproof	Yes	Yes	Yes	No
invulnerable	No	Yes	No	No

bombproof (noun)	invulnerable (noun)
a chamber (often underground) reinforced against bombing and provided with food and living facilities; used during air raids

bombproof (adjective)	invulnerable (adjective)
able to resist the explosive force of bombs and shells	immune to attack; impregnable

bombproof (verb)	invulnerable (verb)
make safe against bombings