Hydrate is traced through this development: Coined in chemistry from Ancient Greek hydor ('water') + the chemical suffix -ate. Hydor descends from Proto-Indo-European *wod-or ('water'). The suffix is part of the word's derivational shape, marking the final grammatical or semantic role while the base supplies the central meaning. As a verb and noun, it means "to supply with water; a compound containing water molecules", so the modern sense keeps the older action or relation visible. Relevant historical forms include Ancient Greek hydor and Proto-Indo-European *wodr. Derivative forms include hydration, hydrated, hydrator; related words include hydrous, hydrogen, anhydrous.