Synonyms of unassailable in English:

unassailable


See US English definition of unassailable

See UK English definition of unassailable

See Spanish definition of inexpugnable

adjective

1‘the world's most unassailable fortress’

SYNONYMS
impregnable, invulnerable, impenetrable, inviolable, invincible, unconquerable, unattackable
secure, safe, safe and sound, well defended, well fortified, fortress-like
strong, stout, indestructible
ANTONYMS

assailable, defenceless

2‘his logic was unassailable’

SYNONYMS
indisputable, undeniable, unquestionable, incontestable, incontrovertible, irrefutable, indubitable, watertight, sound, conclusive, absolute, positive, proven, beyond dispute, beyond question, beyond doubt, beyond a shadow of a doubt, certain, sure, manifest, patent, obvious