HYDRO
| Date | Clue |
|---|---|
| 2022-06-14 | Water power, informally |
| 2021-07-15 | Green power option, informally |
| 2015-03-11 | Eco-friendly power source, informally |
| 2011-12-28 | Prefix with foil or phobia |
| 2001-02-03 | Dynamic start? |
| 1996-07-04 | Form of electric power |
| 1994-06-06 | Kind of power |