Adjective unassailable has 3 senses
- impregnable, inviolable, secure, strong, unassailable, unattackable - able to withstand attack; "an impregnable fortress"; "fortifications that made the frontier inviolable"
Antonym: vulnerable (indirect, via invulnerable)
- unassailable, untouchable - impossible to assail
Antonym: violable (indirect, via inviolable)
- ironclad, unassailable, unshakable, watertight, bulletproof - without flaws or loopholes; "an ironclad contract"; "a watertight alibi"; "a bulletproof argument"
Antonym: contestable (indirect, via incontestable)
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