| spry(adjective, strong, moving, lively, active) |
| spunky |
| stable |
| stallion(adjective, strapping, muscular, well-built, potty) |
| stand tall(expression, adjective, strong, tough, bold) |
| stately(adjective, vigorous, noble, courageous, virile) |
| staunch(adjective, vigorous, noble, courageous, virile) |
| steamroller(adjective, strong, tough, energetic, powerful) |
| steely |
| stouthearted(adjective, strong, tough, bold, resolute) |
| strong-willed |
| strong as an ox(expression, adjective, idiom, strong, tough) |
| strong as brandy(expression, idiom) |
| strong as strong(expression, idiom) |
| stud(adjective, vigorous, noble, courageous, muscular) |
| substantial |
| take-charge(adjective, strong, tough, energetic, powerful) |
| take-over(adjective, strong, tough, intense, energetic) |
| tireless(adjective, strong, moving, energetic, lively) |
| tuna(adjective, strapping, muscular, well-built, potty) |