| rigid(adjective, mean, strong, hard, tough) |
| stubborn(adjective, determined, resolute, uncompromising, obstinate) |
| unyielding(adjective, mean, strong, hard, secure) |
| uncompromising(adjective, mean, hard, secure, tough) |
| obdurate(adjective, person, strong, hard, secure) |
| unbending(adjective, mean, strong, hard, tough) |
| intransigent(adjective, resist, determined, resolute, obstinate) |
| resolute(adjective, strong, hard, secure, tough) |
| inexorable(adjective, mean, strong, hard, tough) |
| firm(noun, adjective, mean, strong, hard) |
| determined(adjective, strong, tough, flat, firm) |
| stiff(adjective, hard, tough, severe, rough) |
| obstinate(adjective, mean, strong, hard, tough) |
| unrelenting(adjective, mean, strong, hard, tough) |
| immovable(adjective, mean, strong, hard, secure) |
| adamant(adjective, person, mean, strong, hard) |
| relentless(adjective, mean, strong, hard, tough) |
| fixed(adjective, mean, strong, hard, secure) |
| set(adjective, strong, hard, secure, tough) |
| unshakable(adjective, mean, strong, hard, secure) |