a republic in western africa, constituting an enclave within senegal extending on both sides of the gambia river. Its capital is banjul, formerly bathurst. The mouth of the river was discovered in 1455 by the portuguese and the english ascended the river 1618-19. The british claim to the region was recognised by the treaty of versailles in 1783. Its status under the british and sierra leone changed several times from 1807 until 1965 when it became independent. The country is named for the river and is a portuguese corruption of the native name ba-dimma, meaning river.