noun
landlocked country
A country entirely surrounded by land, with no direct access to an ocean.
スイスはヨーロッパの内陸国です。
Switzerland is a landlocked country in Europe.
内陸国は海への出口を持たない。
Landlocked countries have no outlet to the sea.
内陸 means 'inland' or 'interior' as a region, while 内陸国 specifically refers to a country that is landlocked.
Compound of 内陸 (ないりく, 'inland') + 国 (こく, 'country').