| byzantine(adjective, hard, complex, involved, dense) |
| grinding(adjective, hard, harsh, cruel, complex) |
| impossible(adjective, support, hard, attitude, unpleasant) |
| inextricable(adjective, hard, complex) |
| labyrinthine(adjective, hard, complex, involved, dense) |
| sad(adjective, hard, complex) |
| troubled(adjective, hard, rough, unhappy, complex) |
| disturbing(adjective, hard, complex) |
| elaborate(adjective, hard, complex, grand, involved) |
| perplexed(adjective, hard, complex) |
| punishing(adjective, hard, complex) |
| sophisticated(adjective, hard, complex, involved, dense) |
| onerous(adjective, dull, hard, great, tough) |
| ticklish(noun, adjective, hard, tough, delicate) |
| Gordian(adjective, hard, complex, involved, dense) |
| composite(adjective, hard, complex) |
| grave(adjective, hard, tough, severe, harsh) |
| hard-nosed(adjective, hard, evil, rough, nasty) |
| hard to understand(expression, adjective, idiom, hard, complex) |
| hefty(adjective, dull, hard, harsh, cruel) |