The Maghreb (المغرب العربي ; also rendered Maghrib (or rarely Moghreb''), meaning "western" in Arabic, is the region of Africa north of the Sahara Desert and west of the Nile — specifically, coinciding with the Atlas Mountains. Geopolitically, the area is reckoned to include Morocco, Western Sahara, Algeria, Tunisia, Libya, and sometimes Mauritania (which is often placed in West Africa instead) - in other words, the member states of the Arab Maghreb Union plus the Western Sahara. An inhabitant or thing of the Maghreb is called a Maghrebian or Maghrebi.
Etymology
The word maghreb is an Arabic term literally meaning "place of setting (of the sun)", and hence "West". It derives from the root ghuroob, meaning "to set" or "to be hidden" (however, it is not used to refer to the setting of the moon). It is also used in a manner similar to the metaphorical use "to be eclipsed", which is used in English.