Enclave - exclave
The word enclave – pronounced with the stress on the first syllable - is applied to the territory of a country or part of a country which is entirely surrounded by the territory of another country: examples are Lesotho, which is entirely surrounded by South Africa; Vatican City, which is entirely surrounded by Italy; and the town of Llívia in the Pyrenees which is part of Spain but entirely surrounded by French territory. A country or part of a country is not an enclave if it is surrounded by the territory of more than one country, so, e.g., Liechtenstein, surrounded by Switzerland on the south and west and Austria on the north and east, is not an enclave.
When the territory of a country or part of a country is partly bordered by the sea but is otherwise completely surrounded by the territory of one other country, it is better to refer to it as a semi-enclave rather than an enclave: so the Spanish territories of Ceuta and Melilla on the Mediterranean coast of North Africa but otherwise entirely surrounded by Morocco are, strictly speaking, semi-enclaves rather than enclaves, as are Monaco, on the Mediterranean coast of Europe and completely surrounded by France; and the Gambia, on the Atlantic coast of West Africa and completely surrounded by Senegal.
The word exclave – also pronounced with the stress on the first syllable - is applied to a part of a country which is separated from the country of which it is a part (the ‘parent’ country) and entirely surrounded by the territory of one or more other countries: thus the Nakhchivan Autonomous Republic is an Azerbaijani exclave – it is separated from the Republic of Azerbaijan, of which it is a part, and completely surrounded by the territories of Turkey, Armenia, and Iran.
Semi-exclave is used analogously to semi-enclave: the word is applied to a part of a country which is separated from the country of which it is a part, is partly bordered by the sea but otherwise entirely surrounded by the territory of one or more other countries. Thus Ceuta and Melilla are Spanish semi-exclaves on the Mediterranean coast of North Africa, while Kaliningrad, on the Baltic coast and completely surrounded by Lithuania and Poland, is a Russian semi-enclave.
Clearly some enclaves are not exclaves (because they are independent states, not separated parts of a ‘parent’ country, e.g., Lesotho and Vatican City) and some exclaves are not enclaves (because they are surrounded by more than one other country, e.g., the Nakhchivan Autonomous Republic). However, it is clearly possible for one and the same territory to be both an enclave and an exclave (e.g., the Spanish town of Llívia in the Pyrenees). For similar reasons, while some semi-enclaves are not semi-exclaves (e.g., the Gambia) and some semi-exclaves are not semi-enclaves (e.g., the Russian semi-exclave of Kaliningrad), it is clearly possible for one and the same territory to be both a semi-enclave and a semi-exclave (e.g., the Spanish semi-exclaves of Ceuta and Melilla).
Enclave and exclave are both compounds derived, ultimately, from the Latin noun clāvis, ‘key’. Enclave comes, through French, from the Old French enclaver, ‘to enclose’, which is assumed to come from an unattested Vulgar Latin inclavāre, ‘to lock up’, formed from the Latin in- and clāvis, ‘key’. Exclave has been formed on the model of enclave.
