E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
Del’ta.
The island formed at the mouth of a river, which usually assumes a triangular form, like the Greek letter (Δ) called delta; as the delta of the Nile, the delta of the Danube, Rhine, Ganges, Indus, Niger, Mississippi, Po, and so on.
