| problematic(adjective, hard, difficult, complex) |
| serious(adjective, hard, difficult, big, heavy) |
| stodgy(adjective, hard, difficult, complex) |
| troublesome(adjective, hard, severe, difficult, heavy) |
| drudgery(noun, adjective, hard, difficult, complex) |
| grave(adjective, hard, difficult, complex) |
| hard to bear(expression, adjective, idiom, hard, difficult) |
| heavy(adjective, dull, tough, severe, difficult) |
| involved(adjective, hard, difficult, complex, awkward) |
| sticky(adjective, hard, difficult, complex, awkward) |
| toilful(adjective, hard, difficult, complex, awkward) |
| troubled(adjective, hard, difficult, complex) |
| cumbersome(adjective, severe, difficult, harsh, pain) |
| irksome(adjective, dull, difficult, heavy, awkward) |
| strenuous(adjective, dull, tough, severe, difficult) |
| demanding(adjective, dull, hard, tough, severe) |
| exhausting(adjective, dull, difficult, awkward, boring) |
| distressing(adjective, hard, rough, difficult, heavy) |
| wearying(adjective, dull, difficult, awkward, boring) |
| bothersome(adjective, tough, severe, difficult, awkward) |