A wadi is a low, dry valley. The term wadi is most commonly used in Arabic-speaking parts of the world.
This word wadi is mainly used to describe valleys and dry creeks and riverbeds in the Middle East and North Africa. A wadi might be a stream during the rainy season and a dry ravine during the rest of the year. Wadi comes from the Arabic wādī, "river" or "watercourse," and it appears in many place names — for example, Guadalajara comes from the Arabic wādī al-hidjārah, "river of stones."