'carbohydrate-free' originates from Modern English, specifically formed from the noun 'carbohydrate' (from New Latin/French roots) and the adjective 'free' (from Old English 'frēo'), where 'carbo-' meant 'coal, carbon' and Greek 'hydōr' meant 'water', and 'frēo' meant 'free' or 'without'.

'carbohydrate' was coined in the 19th century from New Latin/French formations such as 'hydrate de carbone' (combining Latin 'carbo' and Greek-based 'hydrate'), and later the English adjective 'free' (Old English 'frēo') was attached to form the compound adjective 'carbohydrate-free' in modern usage.

Initially, 'carbohydrate' referred specifically to chemical 'hydrates of carbon', and 'free' meant 'not having' or 'without'; over time the compound came to be used especially in dietary contexts to mean 'without carbohydrates'.