| inconceivable(adjective, extraordinary, unusual, belief, unreasonable) |
| unthinkable(noun, adjective, extraordinary, unusual, strange) |
| hopeless(adjective, difficulty, broken, pessimistic, desperate) |
| unbearable(adjective, hard, difficult, pain, complex) |
| complicated(adjective, hard, difficulty, difficult, complex) |
| complex(adjective, hard, difficult, number) |
| knotty(adjective, hard, difficulty, difficult, complex) |
| problematic(adjective, hard, difficult, complex) |
| stubborn(adjective, hard, difficulty, difficult, complex) |
| thorny(adjective, hard, difficulty, difficult, complex) |
| trying(adjective, hard, difficulty, difficult, complex) |
| difficult(adjective, support, hard, attitude, unpleasant) |
| ambitious(adjective, hard, difficult, perfect, complex) |
| impracticable(adjective, difficulty, wild, useless, absurd) |
| hard(adjective, difficult, complex) |
| disturbing(adjective, hard, difficult, complex) |
| far out(adjective, hard, difficult, complex) |
| intricate(adjective, hard, difficulty, difficult, complex) |
| knotted(adjective, hard, difficulty, difficult, complex) |
| rugged(adjective, hard, difficulty, difficult, complex) |