| harsh(adjective, strong, hard, tough, severe) |
| severe(adjective, strong, hard, tough, serious) |
| hard-line(adjective, strong, hard, tough, serious) |
| ineradicable(adjective, continue, confirmed) |
| inveterate(adjective, continue, persistent, obstinate, insistent) |
| irradicable(adjective, continue, confirmed) |
| relentless(adjective, strong, hard, tough, severe) |
| rigid(adjective, strong, hard, tough, severe) |
| set(adjective, continue, persistent, obstinate, insistent) |
| stern(adjective, severe, serious, persistent, unsympathetic) |
| confirmed(adjective, continue, persistent, obstinate, insistent) |
| contrary(adjective, determined, persistent, impulsive, obstinate) |
| cussed(adjective, severe, sharp, nasty, persistent) |
| deep-rooted(adjective, continue, confirmed) |
| determined(adjective, persistent, impulsive, obstinate, insistent) |
| entrenched(adjective, continue, confirmed) |
| firm(adjective, strong, hard, tough, severe) |
| froward(adjective, persistent, impulsive, obstinate, heedless) |
| indomitable(adjective, strong, hard, tough, persistent) |
| inexorable(adjective, strong, hard, tough, persistent) |