| hard-won(adjective, hard, tough, severe, difficult) |
| having colossal strength(expression, adjective, idiom, big, large) |
| humungous(adjective, informal, big, large, grand) |
| inexhaustible(adjective, big, large, grand, huge) |
| irritating(adjective, hard, tough, severe, difficult) |
| labored(adjective, hard, tough, severe, difficult) |
| laborious(adjective, hard, tough, severe, difficult) |
| largest(adjective, big, large, grand, huge) |
| magniloquent(adjective, big, large, grand, huge) |
| never-ending(adjective, big, large, grand, huge) |
| no picnic(adjective, hard, tough, severe, difficult) |
| not easy(adjective, hard, tough, severe, difficult) |
| ocean liner(expression, adjective, idiom, big, large) |
| onerous(adjective, hard, tough, severe, difficult) |
| operose(adjective, hard, tough, severe, difficult) |
| painful(adjective, hard, tough, severe, difficult) |
| ponderous(adjective, big, large, grand, huge) |
| problem(adjective, hard, tough, severe, difficult) |
| problematic(adjective, hard, tough, severe, difficult) |
| prohibitive(adjective, hard, tough, severe, difficult) |