unattackable vs inviolable

unattackable and inviolable both are adjectives.

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

As adjectives, unattackable and inviolable are synonyms defined as:

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

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

unattackable (adjective)	inviolable (adjective)
immune to attack; incapable of being tampered with	incapable of being transgressed or dishonored
	not capable of being violated or infringed
	immune to attack; incapable of being tampered with
	must be kept sacred