| Delphic(adjective, unfathomable, impenetrable, unintelligible) |
| Greek(adjective, incoherent, unfathomable, incomprehensible, impenetrable) |
| baffling(adjective, unfathomable, impenetrable, unintelligible) |
| beats me(expression, unfathomable, impenetrable, opaque, unintelligible) |
| beyond comprehension(expression, adjective, unfathomable, impenetrable, opaque) |
| beyond wildest dreams(expression, idiom, singular, uncommon) |
| clear as mud(expression, adjective, unfathomable, impenetrable, opaque) |
| cryptic(adjective, unfathomable, impenetrable, opaque, unintelligible) |
| enigmatic(adjective, unfathomable, impenetrable, unintelligible) |
| fathomless(adjective, incoherent, unfathomable, incomprehensible, impenetrable) |
| impenetrable(adjective, incoherent, unfathomable, incomprehensible, unintelligible) |
| inapprehensible(singular, uncommon) |
| incognizable(adjective, incoherent, unfathomable, incomprehensible, impenetrable) |
| incomprehensible(singular, uncommon, incoherent, unfathomable, impenetrable) |
| inconceivable(adjective, unfathomable, impenetrable, opaque, unintelligible) |
| ineffable(singular, uncommon) |
| inscrutable(adjective, unfathomable, impenetrable, unintelligible) |
| mysterious(adjective, unfathomable, impenetrable, unintelligible) |
| mystifying(adjective, unfathomable, impenetrable, opaque, unintelligible) |
| obscure(adjective, incoherent, unfathomable, incomprehensible, impenetrable) |