Final answer:
France is the country separated from the UK by the English Channel, which is referred to as La Manche in French.
Step-by-step explanation:
The country that is separated from the UK by the English Channel, known in French as La Manche, is France. This geographical feature creates a natural boundary between the two nations and is an important part of the regional geography of Western Europe.
The Channel stretches from the southern coast of England to the northern coasts of France and is a significant waterway for international shipping, as well as a historic strategic barrier that has influenced many aspects of both British and French history and relations.