| stout(adjective, strong, sound, tough, fit) |
| unshakable(adjective, strong, tough, firm, determined) |
| vigorous(adjective, strong, sound, tough, fit) |
| viscid(adjective, secure, tough, tacky, sticky) |
| bullheaded(adjective, tough, firm, difficult, resist) |
| cohesive(adjective, strong, unyielding, coherence) |
| constant(adjective, strong, tough, flat, firm) |
| decided(adjective, firm, intense, deliberate, determined) |
| enduring(adjective, strong, sound, tough, fit) |
| hard(adjective, strong, determined, fixed, persistent) |
| hearty(adjective, strong, sound, tough, fit) |
| plucky(adjective, strong, tough, determined, bold) |
| secure(adjective, strong, sound, free, tough) |
| steady(adjective, strong, sound, secure, tough) |
| strong-minded(adjective, firm, determined, fixed, serious) |
| tight(adjective, close, strong, hard, free) |
| true(adjective, strong, firm, definite, fixed) |
| unbendable(adjective, determined, resolute, obstinate, uncompromising) |
| bold(adjective, strong, tough, firm, vigorous) |
| business-minded |