Cameroonian

Also, Cameroun. Official name United Republic of Cameroon. an independent republic in W Africa: formed 1960 by the French trusteeship of Cameroun; Southern Cameroons incorporated as a self-governing province 1961. 183,350 sq. mi. (474,877 sq. km).
Capital: Yaoundé.
an active volcano in W Cameroon: highest peak on the coast of W Africa. 13,370 feet (4075 meters).
German Kamerun. a region in W Africa: a German protectorate 1884–1919; divided in 1919 into British and French mandates.
Also called British Cameroons. the NW part of this region: a British mandate 1919–46 and trusteeship 1946–61; by a 1961 plebiscite the S part (Southern Cameroons) joined the United Republic of Cameroon and the N part (Northern Cameroons) joined Nigeria.
Contemporary Examples

Processing the Murder of Eric Ohena Lembembe Neela Ghoshal July 16, 2013
Cameroonian Women Fighting Sexism With Tourism Abena Agyeman-Fisher November 6, 2014

noun
a republic in West Africa, on the Gulf of Guinea: became a German colony in 1884; divided in 1919 into the Cameroons (administered by Britain) and Cameroun (administered by France); Cameroun and the S part of the Cameroons formed a republic in 1961 (the N part joined Nigeria); became a member of the Commonwealth in 1995. Official languages: French and English. Religions: Christian, Muslim, and animist. Currency: franc. Capital: Yaoundé. Pop: 20 549 221 (2013 est). Area: 475 500 sq km (183 591 sq miles) French name Cameroun German name Kamerun
an active volcano in W Cameroon: the highest peak on the West African coast. Height: 4070 m (13 352 ft)
Cameroon [(kam-uh-roohn)]

Note: Cameroon was under British and French control from World War I until 1960.