0
The prefix "hydro-" means water. It comes from the Greek word "hudor," which also means water.
The prefix "hydro" means water, aquatic, aqua, etc...
water as in
hyrated
hydration
dehyrate (etc.)
Greek:
Hydro-
Hydra-
Latin:
Aqua-
Aque-
Aqua. Hydro. As in aquifer or hydro-electric.