The appellation of Delta, or the triangular land, was given to various regions by the Greeks, and implies a space of land bounded by two or more diverging branches of a river, and resembling, in the general form of its area, the fourth letter of the Greek alphabet.
These were the Deltas of the Indus, the Ister, the Rhone, the Padus or Eridanus: but the name was originally and specially conferred upon that triangular region which lies between the Heptanomis, or Middle Egypt, and the Mediterranean sea. Among the Greeks this tract of alluvial soil bore various designations. (τὸ Δέλτα;
the Lower Country, ἡ κάτω χώρα, Ptol. 4.5.55
; τρίγωνος χθὼν Νειλῶτις,
814; Strab. xvi. p.791
; Hdt. 2.6
, seq.; Diod. 1.34
, seq.; Plin. Nat. 5.9. s. 9