east coast
Refers to the eastern coastline of a landmass, often used for the east coast of the United States or Japan.
アメリカの東海岸には大きな都市が多い。
There are many large cities on the east coast of the United States.
東海岸 refers to the eastern coastline of a landmass, while 西海岸 refers to the western coastline, as in the East Coast vs. West Coast of the US.
Compound of 東 (east) and 海岸 (coast).