| persistent(adjective, strain, steady, regular, firmness) |
| firm(adjective, calm, strong, secure, strain) |
| stable(adjective, calm, strong, direct, secure) |
| strong(adjective, strain, firmness, labour, hardiness) |
| consistent(adjective, calm, direct, smooth, right) |
| sound(adjective, calm, strong, secure, strain) |
| steady(adjective, calm, strong, secure, smooth) |
| constant(adjective, calm, strong, secure, smooth) |
| invariable(adjective, calm, strong, secure, strain) |
| unalterable(adjective, calm, strong, secure, strain) |
| fast(adjective, calm, strong, secure, strain) |
| settled(adjective, strong, secure, strain, firm) |
| stabile(adjective, calm, strong, direct, secure) |
| durable(adjective, calm, strong, secure, strain) |
| enduring(adjective, calm, strong, secure, strain) |
| lasting(adjective, calm, strong, secure, strain) |
| permanent(adjective, calm, strong, secure, strain) |
| perpetual(adjective, strain, steady, stable, regular) |
| rigid(adjective, strain, still, fixed, firmness) |
| stationary(adjective, strain, firmness, labour, hardiness) |