Here are some examples:
* Hydration: The process of adding water.
* Hydroelectric: Relating to the generation of electricity from water.
* Hydrocarbon: A compound composed of hydrogen and carbon.
* Hydrolysis: The chemical breakdown of a compound by reaction with water.
* Hydrophobia: Fear of water.
However, it's important to note that in some words, "hydro" may refer specifically to hydrogen. For example:
* Hydrochloric acid: An acid containing hydrogen and chlorine.
* Hydride: A compound containing hydrogen as a negative ion.
Therefore, the exact meaning of "hydro" depends on the context of the word.