| burly(adjective, hard, difficult, complex) |
| oppressive(adjective, dull, hard, severe, firm) |
| sturdy(adjective, calm, person, quality, body) |
| firm(adjective, calm, mean, clear, strong) |
| flinty(adjective, strong, hard, firm, harsh) |
| thug(noun, person, mean, bad, attack) |
| cruel(adjective, mean, strong, hard, cool) |
| roughneck(noun, person, mean, bad, attack) |
| thorny(adjective, hard, difficult, complex, problematic) |
| adamantine(adjective, strong, hard, firm, unreasonable) |
| tight(adjective, strong, hard, difficult, complex) |
| inflexible(adjective, characteristic, mean, strong, hard) |
| hefty(adjective, person, dull, body, strong) |
| hooligan(noun, person, mean, attack, informal) |
| rigid(adjective, characteristic, mean, strong, hard) |
| stout(adjective, calm, person, body, strong) |
| grievous(adjective, hard, severe, difficult, harsh) |
| painful(adjective, bad, hard, severe, difficult) |
| serious(adjective, bad, strong, hard, easy) |
| unbreakable(adjective, strong, firm, solid, stiff) |