Definition from Wiktionary, the free dictionary
A proper name, probably of non-Hebrew origin (perhaps from Egyptian k3š (“Cush, Upper Nubia”).
כּוּשׁ / kûsh / koosh
Proper noun 
- the son of Ham and grandson of Noah, progenitor of the African peoples
- the peoples descended from Cush, Ethiopians, black Africans
- the land occupied by the descendants of Cush located around the middle Nile, Ethiopia
- a Benjamite mentioned only in the title of Psalm 7