electronic Dictionary of Bahamian English (eDBE) with wiki

 [Pan-Creole; cf. DJE Nanga, Nago a Yoruba negro, from Ewe anagó idem; also "term of contempt originally applied by Creole blacks to African-born slaves; now signifying a very black, ugly, stupid negro" DJE; cf. "nagó Yoruba, in Krio, Haitian, Trin., Brazilian Port. and anagó idem in Cuban Sp.; The Nago are a coastal subtribe of the Yoruba from the Dahomey border region" (Hancock 1969:58, 71); cf. also Yoruba Ànàgò Yoruba (old word) (0yedell p.c.)] n. 1. a person descended from the Yorubas of Nigeria:1928 Seven African races are known to have been introduced into the Bahamas: Nan gas, Congos, Congars or Nago bars, Ebos, Mandingos, Fullahs and Hausas (Curry 72). 1976 Bain Town . . . Yorubas . called themselves "N'ongas" (Eneas 22). Congos and Nungas settled in what was then Coconut Grove [South Andros] and they renamed it Congo Town (Andros). Nangos were Africans living "up east" [of Nassau] at the end of the last century (Nassau). cf. YORUBA (Black)

2. an abusive term: A Nango . is low-class, loud-mouth, ill-bred and very dark and ugly (Exuma). A Nango is a crude, uncouth person (Nassau).