| toilsome(adjective, hard, difficult, complex) |
| knotted(adjective, hard, difficulty, difficult, complex) |
| precarious(adjective, hard, difficult, complex) |
| prickly(adjective, easy, sharp, difficult, pain) |
| burdensome(adjective, hard, difficult, complex) |
| impossible(adjective, hard, difficulty, difficult, complex) |
| labyrinthine(adjective, hard, difficulty, difficult, complex) |
| operose(adjective, hard, difficult, complex) |
| oppressive(adjective, hard, difficult, complex) |
| sore(adjective, hard, difficult, complex) |
| spiny(adjective, easy, sharp, pain, sharpness) |
| stressful(adjective, hard, difficult, complex) |
| tight(adjective, hard, difficult, complex) |
| Gordian(adjective, hard, difficult, complex, involved) |
| grinding(adjective, hard, difficult, complex) |
| profound(adjective, hard, difficult, complex) |
| sophisticated(adjective, hard, difficult, complex, involved) |
| stubborn(adjective, hard, difficulty, difficult, complex) |
| byzantine(adjective, hard, difficult, complex, involved) |
| elaborate(adjective, hard, difficult, complex, intricate) |