Pronunciation: (tan"zu-nē'u; Swahili. tän-zä-nē'ä),[key] —n. a republic in E Africa formed in 1964 by the merger of the republic of Tanganyika and the former island sultanate of Zanzibar (including Pemba and adjacent small islands). 24,800,000; 364,881 sq. mi. (945,037 sq. km).Cap.: Dodoma. Official name, United Republic of Tanzania.