Delta

Del″ta (?), n.; pl.Deltas (#). [Gr. δέλτα, the name of the fourth letter of the Greek alphabet (the capital form of which is Δ, Eng. D), from the Phœnician name of the corresponding letter. The Greeks called the alluvial deposit at the mouth of the Nile, from its shape, the Delta of the Nile.] A tract of land shaped like the letter delta (Δ), especially when the land is alluvial and inclosed between two or more mouths of a river; as, the delta of the Ganges, of the Nile, or of the Mississippi.