If one nation, or an independent piece of territory, is surrounded totally by one other it is called an enclave.
If it is not an independent piece of territory, but is a part of a different country, it is called an exclave.
The term is "landlocked"
Lesotho is a country that is completely surrounded by another country. It is surrounded by South Africa
The tiny 61 kilometer San Marino, is completely surrounded by Italy. Although it is rather odd, San Marino is older than Italy by over 1000 years! The Republic of San Marino was founded around year 310 C.E., Making it the oldest republic in the world.
Vatican City, San Marino, and Lesotho.
Landlocked.
No, it is not completely encircled by South America. Lesotho is a country in the continent of Africa, and is completely surrounded by the country called South Africa.
The region of a country bordering on another or a line, barrier, etc., marking such a border is called a frontier. A frontier is also the edge of the settled area of a country.
No. However there is a city called Cotonou in the country called Benin.
It might be an urban agglomeration, a conurbation or a metropolitan area.
They are called immigrants, a person that comes to a country where they were not born, to settle there.
No, it is not completely encircled by South America. Lesotho is a country in the continent of Africa, and is completely surrounded by the country called South Africa.
There is no Batican City but there is a country called Vatican City. It is the smallest country in the world and is completely surrounded by the city of Rome, in Italy.
Islands
They are called islands
All islands are completely surrounded by water. That is what makes them islands. Since all islands are surrounded by water, there is no specific name for that type of island.
A lake?
It is an island.
island
This would be called an island. Land surrounded on three sides may be called a peninsula or cape.
acoelomate
A body of water almost completely surrounded by water is called an ocean. Oceans will often run into each other.
A freshwater lake.