| persevering(adjective, quiet, understanding, strong, tough) |
| determined(adjective, strong, tough, flat, firm) |
| indefatigable(adjective, strong, firm, determined, steady) |
| resolute(adjective, strong, tough, flat, firm) |
| relentless(adjective, strong, tough, severe, continue) |
| dogged(adjective, strong, tough, firm, energetic) |
| continuous(adjective, continue, firm, certain, steady) |
| pertinacious(adjective, strong, tough, continue, firm) |
| unremitting(adjective, strong, continue, firm, determined) |
| tireless(adjective, strong, firm, energetic, determined) |
| obstinate(adjective, strong, tough, continue, firm) |
| unflagging(adjective, strong, firm, certain, determined) |
| insistent(adjective, continue, determined, resolute, demanding) |
| unrelenting(adjective, tough, firm, certain, determined) |
| unwavering(adjective, strong, flat, firm, intense) |
| incessant(adjective, strong, continue, firm, determined) |
| staunch(adjective, strong, tough, flat, firm) |
| unfaltering(adjective, strong, firm, intense, deliberate) |
| fixed(adjective, strong, tough, flat, firm) |
| unceasing(adjective, strong, continue, firm, determined) |