unattackable vs unassailable

unattackable and unassailable both are adjectives.

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

As adjectives, unattackable and unassailable are synonyms defined as:

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

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

unattackable (adjective)	unassailable (adjective)
immune to attack; incapable of being tampered with	without flaws or loopholes
	impossible to assail
	immune to attack; incapable of being tampered with