| not easy(expression, tough, severe, painful, problematic) |
| plodding |
| problem(tough, severe, painful, problematic, trying) |
| problematic(tough, severe, difficult, awkward, painful) |
| problematical(adjective, difficult, complex, awkward, demanding) |
| prohibitive(tough, severe, painful, problematic, trying) |
| rigid(tough, severe, painful, problematic, trying) |
| rugged(adjective, hard, tough, rough, difficult) |
| serious(adjective, hard, tough, severe, rough) |
| sisyphean |
| sticky(adjective, tough, rough, difficult, heavy) |
| straining |
| terrible(adjective, tough, rough, difficult, heavy) |
| tiresome(adjective, tough, difficult, problematic, trying) |
| toilful(adjective, tough, rough, difficult, heavy) |
| tricky(adjective, difficult, complex, awkward, demanding) |
| unsparing(adjective, tough, rough, difficult, harsh) |
| unyielding(tough, severe, painful, problematic, trying) |
| upstream(tough, severe, painful, problematic, trying) |
| weighty(adjective, heavy) |