a.
1.
Unassailable, inexpugnable, not to be taken by assault, not to be stormed, secure from capture, tenable against all odds.
2.
Unassailable, invulnerable, invincible, immovable, not to be shaken, irrefragable.
a.
1.
Unassailable, inexpugnable, not to be taken by assault, not to be stormed, secure from capture, tenable against all odds.
2.
Unassailable, invulnerable, invincible, immovable, not to be shaken, irrefragable.
Soule. Dictionary of English synonyms. Словарь английских синонимов. 2012