| potent(adjective, strong, sound, tough, heavy) |
| strong(adjective, set, hard, sound, tough) |
| tough(adjective, strong, hard, sound, continue) |
| hale(adjective, strong, sound, tough, solid) |
| hard(adjective, set, strong, tough, continue) |
| hardy(adjective, set, strong, hard, sound) |
| horny |
| rugged(adjective, set, strong, hard, sound) |
| stalwart(adjective, strong, hard, sound, tough) |
| concrete |
| dense(adjective, set, strong, hard, tough) |
| flinty(adjective, strong, hard, firm, solid) |
| forceful(adjective, strong, sound, tough, solid) |
| forcible(adjective, strong, sound, tough, solid) |
| hard-bitten(adjective, strong, hard, continue, solid) |
| hearty(adjective, strong, sound, tough, solid) |
| lusty(adjective, strong, hard, solid, stiff) |
| mighty(adjective, strong, hard, sound, tough) |
| obdurate(adjective, strong, hard, tough, firm) |
| obstinate(adjective, tough, firm, fixed, serious) |