| hard(adjective, dull, great, tough, easy) |
| arduous(adjective, dull, hard, great, tough) |
| tough(adjective, dull, hard, great, easy) |
| laborious(adjective, dull, hard, great, tough) |
| burdensome(adjective, dull, hard, tough, severe) |
| complex(adjective, hard, delicate, complex, awkward) |
| tricky(noun, adjective, hard, delicate, unpleasant) |
| knotty(adjective, hard, rough, delicate, complex) |
| intricate(adjective, hard, delicate, complex, awkward) |
| severe(adjective, hard, tough, rough, harsh) |
| complicated(adjective, hard, delicate, complex, awkward) |
| problematic(adjective, hard, tough, delicate, complex) |
| troublesome(adjective, hard, tough, severe, evil) |
| rough(adjective, hard, great, tough, severe) |
| trying(adjective, dull, hard, tough, severe) |
| toilsome(adjective, hard, great, tough, difficulty) |
| involved(adjective, hard, delicate, complex, awkward) |
| thorny(adjective, hard, rough, delicate, complex) |
| painful(adjective, hard, complex, troublesome, agonizing) |
| sensitive(adjective, hard, delicate, tender, lively) |