| persistent(adjective, feature, state, characteristic, strong) |
| stiff(adjective, feature, state, characteristic, set) |
| rigid(adjective, feature, state, characteristic, mean) |
| strong(adjective, calm, good, set, strong) |
| stable(adjective, calm, good, strong, hard) |
| hard(adjective, adverb, feature, state, characteristic) |
| unyielding(adjective, set, mean, clear, strong) |
| sound(noun, adjective, calm, strong, hard) |
| steadfast(adjective, feature, state, characteristic, calm) |
| consistent(adjective, strain, solid, certain, determined) |
| unfluctuating(adjective, calm, strong, secure, strain) |
| determined(adjective, good, set, clear, strong) |
| steady(adjective, feature, state, characteristic, calm) |
| resolute(adjective, calm, close, set, clear) |
| inflexible(adjective, mean, strong, hard, secure) |
| fixed(adjective, characteristic, calm, change, set) |
| stubborn(adjective, resolute, determined, uncompromising, obstinate) |
| constant(adjective, calm, good, close, strong) |
| fast(adjective, adverb, calm, close, strong) |
| substantial(adjective, calm, close, strong, hard) |