Hydrophobia reaches English through Latin from Greek water and fear components. The word has also been used in medical descriptions connected with rabies. The puzzle asks about the linguistic construction, which remains water plus fear.
This view explains the components. They are pieces of one construction, not consecutive borrowing stages.
Sources
- Merriam-Webster · hydrophobia
Formation of the word.
- Merriam-Webster · hydro-
Meaning and history of this component.
- Merriam-Webster · -phobia
Meaning and history of this component.