| rancorous(adjective, mean, evil, nasty, harsh) |
| set(adjective, hard, resolute, rigid, inflexible) |
| solid |
| stiff(adjective, harsh, cruel, determined, fierce) |
| uncompassionate(adjective, animal, mean, hard, tough) |
| unwavering(adjective, determined, resolute, uncompromising, unshakeable) |
| avenging(adjective, mean, hateful, malicious, spiteful) |
| barbarous(adjective, animal, appearance, mean, hard) |
| brutal(adjective, mean, severe, evil, nasty) |
| cold(adjective, mean, hard, harsh, indifferent) |
| hard-boiled(adjective, mean, strong, hard, tough) |
| hard-hearted(adjective, mean, hard, tough, evil) |
| hard-nosed(adjective, mean, strong, hard, tough) |
| hardheaded(adjective, strong, hard, tough, firm) |
| harsh(adjective, mean, strong, hard, tough) |
| heartless(adjective, mean, hard, severe, evil) |
| inconvincible(adjective, determined, resolute, uncompromising, unshakeable) |
| indurate(adjective, mean, hard, determined, resolute) |
| inhumane(adjective, animal, mean, hard, tough) |
| iron-willed(adjective, determined, resolute, uncompromising, unshakeable) |