| difficult(adjective, hard, rough, difficult, delicate) |
| knotty(adjective, hard, difficulty, difficult, delicate) |
| tough(adjective, hard, difficult, complex, problematic) |
| hard(adjective, rough, difficult, delicate, complex) |
| complicated(adjective, hard, difficulty, difficult, delicate) |
| complex(adjective, hard, difficult, delicate, awkward) |
| tricky(adjective, hard, difficult, complex, complicated) |
| intricate(adjective, hard, difficulty, difficult, delicate) |
| rugged(adjective, hard, difficulty, difficult, complex) |
| sticky(adjective, hard, difficult, complex, problematic) |
| severe(adjective, hard, difficult, complex, problematic) |
| problematic(adjective, hard, difficult, delicate, complex) |
| rough(adjective, hard, difficult, complex, sharpness) |
| trying(adjective, hard, difficulty, difficult, complex) |
| arduous(adjective, hard, difficult, complex, demanding) |
| involved(adjective, hard, difficult, delicate, complex) |
| laborious(adjective, hard, difficult, complex) |
| nasty(adjective, hard, difficult, complex) |
| painful(adjective, hard, difficult, complex) |
| sensitive(adjective, hard, difficult, complex) |