A large and distinct section of a continent can be called a subcontinent. Many subcontinents are separated from the rest of a continent by geographical features.
One of the most well-known subcontinents is the Indian subcontinent, which was once the country of India, but today includes Pakistan and Bangladesh. This area makes up a large section of Asia, in the form of a long peninsula that sits on a separate tectonic plate from the rest of the continent. Alaska is another subcontinent, geographically separate from the rest of North America.