| sharp(adjective, energetic, enthusiastic, determined, earnest) |
| sharpy |
| snappy(adjective, strong, tough, energetic, powerful) |
| soaring(adjective, energetic, enthusiastic, determined, ardent) |
| sound(adjective, strong, tough, intense, energetic) |
| spanking(adjective, strong, great, tough, energetic) |
| spark plug(noun, expression, device, rock, fuse) |
| spirited(adjective, strong, tough, energetic, powerful) |
| sprightly(adjective, strong, moving, energetic, lively) |
| spry(adjective, strong, moving, energetic, lively) |
| stalwart(adjective, strong, moving, lively, active) |
| steady |
| steamroller(adjective, strong, tough, energetic, violent) |
| strapping(adjective, strong, tough, intense, energetic) |
| strenuous(adjective, strong, tough, energetic, powerful) |
| stringent(adjective, strong, energetic, violent, powerful) |
| striving(adjective, energetic, enthusiastic, determined, ardent) |
| strong(adjective, tough, energetic, violent, powerful) |
| strong as an ox(expression, adjective, idiom, strong, tough) |
| sturdy(adjective, strong, tough, energetic, powerful) |