Noun

(en noun)

The fourth letter of the modern Greek alphabet .

A landform at the mouth of a river where it empties into a body of water.

The letter D in the ICAO spelling alphabet, which assigns words to letters of the alphabet.

(mathematics) The symbol .

(computing, informal) A small but noticeable effect, compare with epsilon.

This will slow the main code path down, but only by delta .

(computing) The set of differences between two versions of a file.

When you update the file, the system will only save the deltas .

(surveying) The angle subtended at the center of a circular arc.

A type of cargo bike that has one wheel in front and two in back.

Noun

(en noun)

An elongated depression between hills or mountains, often with a river flowing through it.

* {{quote-magazine, date=2013-08-16, author= John Vidal

, volume=189, issue=10, page=8, magazine=(The Guardian Weekly) , title= Dams endanger ecology of Himalayas , passage=Most of the Himalayan rivers have been relatively untouched by dams near their sources. Now the two great Asian powers, India and China, are rushing to harness them as they cut through some of the world's deepest valleys .}}

The area which drains into a river.

Any structure resembling one, e.g., the meeting point of two pitched roofs.

The internal angle formed by the intersection of two sloping roof planes.