| Basic |
| Extreme |
| Drastic |
| Far out! |
| Sweeping |
| Extremist |
| Out there |
| Avant-garde |
| Fundamental |
| Left-winger |
| On the fringe |
| Groundbreaking |
| Square root sign |
| Far from moderate |
| Math class symbol |
| Square root symbol |
| Root-and-branch man |
| Political extremist |
| Moderate's opposite |
| Profoundly different |
| Progressive — car dial (anag) |
| One holding strong reformist views |
| One seeking root and branch reform |
| Thoroughgoing — (popularly) extremist |
| Like activists who have extreme views and demand total reform |