impenetrable Synonyms - page 2

undividable uninjectable unreceptive unsolved untraversable untrod unreadable water-repellent unintelligible airtight gruelling kabbalistic unapproachable leakproof light-tight unbreakable unbridgeable bulletproof unassailable watertight neck and neck unsubduable nonporous water-resistant wakeless abstruse compressed condensed confusing cryptic crystallizable delphic difficult enigmatic esoteric fathomless firm flinty gordian grumous gummous hard complicated complex adamantine alchemic alchemistic appressed arcane baffling