Wadi (Arabic: وادي, translit. wādī, Hebrew: ואדי vādī)" is the Arabic and Hebrew term traditionally referring to a valley. In some instances, it may refer to a dry (ephemeral) riverbed that contains water only during times of heavy rain.
The term wādī is very widely found in Arabic toponyms.
Some Spanish toponyms are derived from Andalusian Arabic where wādī was used to mean a permanent river, for example: Guadalcanal from wādī al-Qanal = "river of refreshment stalls", Guadalajara from wādī al-hidjārah = "river of stones", or Guadalquivir from al-wādī al-kabīr = "the great river". Seasonal streams, frequent in south-east Spain, are called ramblas instead.
Wadi is also a word commonly used in the Hindustani language (both Urdu and Hindi variants) to refer to a valley.
In the Maghreb, the term wadi (wad in Maghrebi Arabic, sometimes transcribed Oued) is applied to all rivers including regular ones.