impregnable vs inviolable

impregnable and inviolable both are adjectives.

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

As adjectives, impregnable and inviolable are synonyms defined as:

impregnable and inviolable: immune to attack; incapable of being tampered with

Other synonyms of impregnable include secure, strong, unassailable, unattackable.

impregnable (adjective)	inviolable (adjective)
capable of conceiving	incapable of being transgressed or dishonored
immune to attack; incapable of being tampered with	not capable of being violated or infringed
incapable of being overcome, challenged or refuted	immune to attack; incapable of being tampered with
	must be kept sacred