SEAS
n. countable A2 Elementary US //ˈsiz// UK //sˈiːz// seas
n. large areas of salty water that cover much of the Earth. They are smaller than oceans and are often partly surrounded by land.
n. large bodies of saline water that are part of the world's hydrosphere. Often used to refer to specific regions of the ocean or the ocean in general when used in the plural.
Many different kinds of fish live in the deep seas.
The explorers spent many months traveling across the high seas to reach the new continent.
Environmental scientists are concerned about how rising global temperatures and plastic pollution are affecting the delicate ecosystems within our world's seas.
Usage
Commonly used in the plural ('the seas') to refer to the global ocean or in phrases like 'the high seas'.