| strong-willed(adjective, strong, tough, firm, determined) |
| unyielding(adjective, strong, tough, flat, firm) |
| bold(adjective, resolute, tenacious) |
| business-minded |
| decided(adjective, strong, firm, resolution, serious) |
| faithful(adjective, strong, firm, determined, bold) |
| headstrong(adjective, tough, firm, unreasonable, grim) |
| indomitable(adjective, strong, firm, determined, steady) |
| inflexible(adjective, strong, tough, flat, firm) |
| obdurate(adjective, strong, tough, flat, firm) |
| unrelenting(adjective, perseverance) |
| abiding(verb, adjective, set, strong, flat) |
| adamant(adjective, strong, tough, flat, firm) |
| fixed(adjective, strong, tough, flat, firm) |
| inexorable(adjective, tough, firm, determined, unreasonable) |
| rigid(adjective, tough, firm, determined, unreasonable) |
| uncompromising(adjective, resolute) |
| undaunted(adjective, tenacious) |
| undeviating(adjective, strong, certain, definite, perseverance) |
| brave(adjective, determined, resolution, resolute, courageous) |