| strong-willed(adjective, strong, tough, firm, intense) |
| unchangeable(adjective, calm, strong, secure, flat) |
| intent(adjective, set, strong, severe, flat) |
| earnest(adjective, close, set, severe, firm) |
| stout(adjective, calm, strong, tough, firm) |
| true(adjective, close, strong, tough, correct) |
| unhesitating(adjective, firm, certain, determined, resolution) |
| hanging tough(expression, adjective, determined, usual, regular) |
| untiring(adjective, determined, persevering) |
| valiant(adjective, strong, tough, firm, ready) |
| definite(adjective, strong, easy, flat, firm) |
| devoted(adjective, close, strong, correct, keen) |
| faithful(adjective, close, correct, keen, firm) |
| mulish(adjective, tough, determined, obstinate, stubborn) |
| positive(adjective, intense, certain, deliberate, determined) |
| serious(adjective, set, severe, firm, sensible) |
| single-minded(adjective, tough, firm, sensible, solid) |
| strenuous(adjective, activity, energetic, determined, zealous) |
| sturdy(adjective, calm, strong, tough, firm) |
| unchanging(adjective, close, hard, correct, severe) |