invulnerable vs impregnable

invulnerable and impregnable both are adjectives.

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

invulnerable (adjective)	impregnable (adjective)
immune to attack; impregnable	capable of conceiving
	immune to attack; incapable of being tampered with
	incapable of being overcome, challenged or refuted