Chad (chăd, chäd) [key], officially Republic of Chad, republic (2005 est. pop. 9,826,000), 495,752 sq mi (1,284,000 sq km), N central Africa. Chad is bordered by the Central African Republic on the south, Sudan on the east, Libya on the north, and Cameroon, Niger, and Nigeria on the west. Ndjamena is the capital and largest city.
