| operose(adjective, characteristic, difficulty, hardship) |
| oppressive(adjective, characteristic, burden, problem) |
| paradoxical(adjective, characteristic, difficulty, hardship) |
| perverse(adjective, characteristic, difficulty, hardship) |
| picky(adjective, characteristic, difficulty, hardship) |
| pretentious(adjective, characteristic, difficulty, complication) |
| problematic(adjective, characteristic, difficulty, hardship) |
| problematical(adjective, characteristic, difficulty, hardship) |
| profound(adjective, characteristic, difficulty, hardship) |
| prohibitive(adjective, characteristic, difficulty, hardship) |
| puzzling(adjective, characteristic, difficulty, hardship) |
| rambling(adjective, characteristic, difficulty, hardship) |
| recalcitrant(adjective, characteristic, difficulty, hardship) |
| refractory(adjective, characteristic, difficulty, hardship) |
| rigid(adjective, characteristic, difficulty, hardship) |
| rude(adjective, characteristic, difficulty, hardship) |
| sticky(adjective, characteristic, difficulty, complication) |
| stiff(adjective, characteristic, difficulty, hardship) |
| subtle(adjective, characteristic, difficulty, hardship) |
| superincumbent(adjective, characteristic, burden, problem) |