| uncompromising(adjective, tough, firm, deliberate, determined) |
| uniform(adjective, steady, regular, even, constant) |
| urgent(adjective, continue) |
| bulldogged(adjective, determined, tenacious) |
| contumacious(adjective, tough, firm, determined, obstinate) |
| definite(adjective, strong, firm, certain, unyielding) |
| deliberate(adjective, intense, determined, resolute, intentional) |
| even(adjective, steady, regular, constant, uniform) |
| fearless(adjective, resolute) |
| monotonous(adjective, common, regular, normal, constant) |
| never-ending(adjective, determined, steady, regular, even) |
| ongoing(adjective, continue) |
| perdurable(adjective, continue, sturdy, constant, enduring) |
| protracted(adjective, continue, continuous, lasting, continuing) |
| recalcitrant(adjective, tough, firm, obstinate, stubborn) |
| solid(adjective, strong, tough, firm, certain) |
| spunky(adjective, resolute, tenacious) |
| strong-minded(adjective, firm, determined, fixed, serious) |
| thorough(adjective, resolute) |
| unbending(adjective, strong, tough, severe, flat) |