carbohydrate (n.) Look up carbohydrate at
1851, from carbo-, comb. form of carbon, + hydrate (n.), denoting compound produced when certain substances combine with water, from Greek hydor "water" (see water (n.1)).
The name carbohydrate was given to these compounds because, in composition, they are apparently hydrates of carbon. In structure, however, they are far more complex. [Flood]