delta

An area of land formed by sand and mud where a river flows into a lake or sea.

• The river has a wide delta.
• Many birds live in the delta.
• Floods brought fresh mud to the delta.

Common phrases: river delta, Nile delta, delta region

The fourth letter of the Greek alphabet, written as Δ or δ.

• Delta is a Greek letter.
• Write a lowercase delta beside the number.
• The teacher showed us how to pronounce delta.

Common phrases: Greek delta, lowercase delta, capital delta, small delta

The symbol Δ used to show how much a quantity changes.

• Delta shows the change in temperature.
• Calculate delta by subtracting the first value from the second.
• The engineer used delta V to describe the change in speed.

Common phrases: delta V, delta value, calculate delta