a nearly flat plain of alluvial deposit between diverging branches of the mouth of a river, often, though not necessarily, triangular: the Nile delta. (usually initial capital letter) a word used in communications to represent the letter D. read more
Define delta. delta synonyms, delta pronunciation, delta translation, English dictionary definition of delta. An area of the south-central United States extending on either side of the Mississippi River from Memphis, Tennessee, to Vicksburg, Mississippi. read more