Akademik

inexpugnable
I adjective defensible, formidable, hardy, immune, impenetrable, imperdible, impregnable, indomitable, inexpugnabilis, inextinguishable, insuperable, insurmountable, invincible, inviolable, invulnerable, irresistible, mighty, potent, powerful, protected, puissant, redoubtable, resistless, safe, secure, secure from capture, strong, sturdy, tenable, unassailable, unattackable, unbeatable, unbreakable, unchallengeable, unconquerable, unsubduable, unyielding II index immune, insurmountable, invincible

Burton's Legal Thesaurus. . 2006