impenetrable Synonyms - page 2

undefeatable unattackable unreadable unscalable unanalyzable untrod untraversable unsolved unreceptive uninjectable undividable uncomprehensible un-come-at-able soundproof water-repellent water-resistant leakproof unknowable unapproachable antifeminist kabbalistic gruelling airtight unintelligible light-tight unbreakable nonporous unsubduable neck and neck mothproof watertight unassailable bulletproof unbridgeable wildering jungly abstruse fathomless esoteric enigmatic dura difficult devastating delphic crystallizable firm flinty heaped hard-handed hardened