| steady(adjective, firm, true, faithful) |
| stiff(adjective, harsh, cruel, determined, fierce) |
| strict(adjective, harsh, cruel, determined, fierce) |
| stringent(adjective, harsh, cruel, determined, fierce) |
| unalterable(adjective, determination, firmness, inevitability) |
| uncontainable(adjective, wild, vivacious, buoyant, effervescent) |
| undaunted(adjective, determination, bravery, persistence) |
| undeviating(adjective, harsh, cruel, determined, fierce) |
| unfailing(adjective, determination, bravery, persistence) |
| unfaltering(adjective, determination, bravery, persistence) |
| unflinching(adjective, harsh, cruel, determined, fierce) |
| unforgiving(adjective, harsh, cruel, determined, fierce) |
| unlimited(adjective, determination, bravery, persistence) |
| unmanageable(adjective, wild, vivacious, effervescent, uncontrollable) |
| unquenchable(adjective, wild, vivacious, buoyant, effervescent) |
| unrestrainable(adjective, wild, vivacious, buoyant, effervescent) |
| unrestrained(adjective, wild, vivacious, effervescent, uncontrollable) |
| unswerving(adjective, determination, bravery, persistence) |
| sure(adjective, firm, true, dependable) |
| unconquerable(adjective, determination, bravery, persistence) |