noun \ˈdel-tə\

: the fourth letter of the Greek alphabet

: a piece of land shaped like a triangle that is formed when a river splits into smaller rivers before it flows into an ocean

: an area of low land along the Mississippi River that is mainly in the state of Mississippi

Full Definition of DELTA

:  the 4th letter of the Greek alphabet — see alphabet table
:  something shaped like a capital Greek delta; especially :  the alluvial deposit at the mouth of a river
:  an increment of a variable —symbol Δ
del·ta·ic \del-ˈtā-ik\ adjective

Origin of DELTA

Middle English deltha, from Greek delta, of Semitic origin; akin to Hebrew dāleth daleth
First Known Use: 13th century

Other Geology Terms

anthracite, boulder, cwm, erratic, igneous, intrusive, mesa, sedimentary, silt, swale



Definition of DELTA

:  fourth in position in the structure of an organic molecule from a particular group or atom —symbol δδ

First Known Use of DELTA

circa 1929

Other Chemical Engineering Terms

alkali, cation, decant, hygroscopic, isotope, oxidize, slurry, solute, viscous


Definition of DELTA

—a communications code word for the letter d

First Known Use of DELTA



geographical name \ˈdel-tə\

Definition of DELTA

municipality Canada in SW British Columbia pop 99,863


noun    (Concise Encyclopedia)

Low-lying plain composed of stream-borne sediments deposited by a river at its mouth. Deltas have been important to humankind since prehistoric times. Sands, silts, and clays deposited by floodwaters were extremely productive agriculturally; and major civilizations flourished in the deltaic plains of the Nile and Tigris-Euphrates rivers. In recent years geologists have discovered that much of the world's petroleum resources are found in ancient deltaic rocks. Deltas vary widely in size, structure, composition, and origin, though many are triangular (the shape of the Greek letter delta).


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