West Country 
The south-western counties of England.
- hydrometric
- hydrometry
- hydronic
- hydronium ion
- hydropathic
- hydropathist
- hydropathy
- hydroperoxide
- hydroperoxyl
- hydrophilic
- hydrophilicity
- hydrophilous
- hydrophily
- hydrophobia
- hydrophobic
- hydrophobicity
- hydrophone
- hydrophyte
- hydrophytic
- hydroplane
- hydroponic
- hydroponically
- hydroponics
- hydropower
- hydroquinone