Sudan

wiktionary

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From Arabic سُودَان‎ (sūdān, “black people”), plural of أَسْوَد‎ (ʾaswad). [1]

etymonline

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Sudan

1842, from Arabic Bilad-al-sudan, literally "country of the blacks" (originally the stretch of Africa between the Sahara and the equator), from sud, plural of aswad (fem. sauda) "black." In early use also Soudan, from French. Related: Sudanese.