| beyond comprehension(expression, unfathomable, impenetrable, opaque, unintelligible) |
| clear as mud(expression, unfathomable, impenetrable, opaque, unintelligible) |
| cryptic(unfathomable, impenetrable, opaque, unintelligible, puzzling) |
| downreaching(adjective, low-set, depth, low-lying, subjacent) |
| enigmatical |
| enormous(adjective, incalculable, immeasurable) |
| gaping |
| great(adjective, incalculable, immeasurable) |
| incalculable(adjective, immeasurable) |
| inconceivable(unfathomable, impenetrable, opaque, unintelligible, puzzling) |
| invaluable(adjective, incalculable, immeasurable) |
| low(low-set, low-lying, subjacent) |
| mystifying(unfathomable, impenetrable, opaque, unintelligible, puzzling) |
| not understandable(expression, incoherent, unfathomable, incomprehensible, impenetrable) |
| opaque(incoherent, unfathomable, incomprehensible, impenetrable, unintelligible) |
| perplexing(unfathomable, impenetrable, opaque, unintelligible, puzzling) |
| plunging |
| puzzling(unfathomable, impenetrable, opaque, unintelligible) |
| sunken(adjective, deep) |
| tremendous(adjective, incalculable, immeasurable) |