SEAS
n. countable A2 Elementary US //ˈsiz// UK //sˈiːz// seas
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'.