| laborious(adjective, hard, severe, rough, difficult) |
| Gordian(adjective, hard, difficult, complex, involved) |
| severe(adjective, hard, difficult, violent, complex) |
| toilsome(adjective, hard, difficult, complex, awkward) |
| profound(adjective, hard, difficult, complex) |
| lumpy(adjective, hard, difficult, complex, coarse) |
| trying(adjective, hard, difficulty, difficult, complex) |
| burdensome(adjective, hard, difficult, complex, awkward) |
| grinding(adjective, hard, difficult, complex, awkward) |
| involute(adjective, hard, simple, difficult, complex) |
| sensitive(adjective, hard, difficult, complex) |
| impossible(adjective, hard, difficulty, difficult, complex) |
| inextricable(adjective, hard, difficult, complex) |
| nasty(adjective, hard, evil, difficult, complex) |
| operose(adjective, hard, severe, rough, difficult) |
| oppressive(adjective, hard, difficult, complex) |
| painful(adjective, hard, difficult, complex) |
| sinuous(adjective, hard, difficult, complex) |
| stressful(adjective, hard, difficult, complex) |
| tight(adjective, hard, difficult, complex) |