| dour(adjective, tough, severe, sharp, nasty) |
| frigid(adjective, person, mean, cool, unpleasant) |
| gruelling |
| hateful(adjective, person, mean, evil, nasty) |
| icy(adjective, person, mean, cool, tough) |
| immovable(adjective, mean, strong, tough, cruel) |
| implacable(adjective, mean, strong, tough, severe) |
| inclement(noun, adjective, nature, severe, rough) |
| inconsiderate(adjective, person, mean, tough, severe) |
| indifferent(adjective, person, mean, cool, unpleasant) |
| inhuman(adjective, mean, tough, severe, evil) |
| intractable(adjective, tough, sharp, firm, fixed) |
| intransigent(adjective, severe, determined, stiff, resolute) |
| powerful(adjective, person, body, strong, great) |
| rocky(adjective, firm, delicate, stiff, rigid) |
| stringent(adjective, tough, severe, rough, firm) |
| excruciating(adjective, evil, rough, nasty, harsh) |
| terrible(adjective, rough, difficult, harsh, tender) |
| tiring(adjective, dull, difficult, full, awkward) |
| uncompassionate(adjective, mean, cool, tough, severe) |