Chad (French: Tchad, Arabic: تشاد ) ) , The official name is the Republic of Chad , a landlocked state in Central Africa. It is bounded on the north by Libya , on the east by Sudan , on the south by the Central African Republic , on the southwest by Cameroon and Nigeria , and on the west by Niger. Chad is sometimes referred to as the "Dead Heart of Africa" because of its location away from the sea and its desert climate. Chad is also called Shad because of the change in the Bengali language. Chad can be divided into three geographic regions: the Sahara Desert in the north , the barren coastal belt in the middle , and the relatively fertile Sudanese Savannah in the south. Lake Chad is the largest body of water in the country and the second largest in Africa. The lake is named after the country Chad. Amy Kausi Chad is the highest mountain in the Tibetan Mountains in the Sahara. The capital, Inzamina, is the largest city in the country. Chad is home to more than 200 ethnic and linguistic groups. French and Arabic are the official languages here. Islam is the most prevalent religion.