'Aquadag' originates from modern English, coined as a trademark by the Acheson company; it combines the Latin element 'aqua', where 'aqua' meant 'water', and the coined suffix 'dag', where 'dag' denoted a graphite dispersion (a company product-name element).

'Aquadag' grew out of early 20th-century product-naming patterns used by graphite/chemical manufacturers (for example other 'dag' products such as 'Electrodag') and was introduced to identify a water-based graphite dispersion; it remained primarily a brand/technical term rather than a common lexical word.

Initially, it meant specifically the Acheson-brand water-based graphite dispersion; over time it has continued to refer to that product or similar water-based colloidal graphite coatings in technical contexts.