1. A region of northern Africa south of the Sahara and north of the equator. It extends across the continent from the Atlantic coast to the mountains of Ethiopia.

2. A country of northeast Africa south of Egypt. Northern Sudan formed part of the ancient kingdoms of Nubia and Cush. Conquered by Egypt in 1820-1822 and jointly administered by Great Britain and Egypt after 1899, Sudan achieved independence in 1956. Khartoum is the capital and Omdurman is the largest city. In 2011, the southern part of the country seceded, forming the republic of South Sudan.