Sea (noun)

1. A large expanse of salt water that covers most of the earth's surface and is home to a wide variety of life.
2. The waters of an ocean or large lake.
3. An area of the ocean or other large body of water that is partly enclosed by land.

Origin:

Old english sǣ, of germanic origin; related to dutch zee and german see.

Examples:

1. We went for a walk on the sea shore.
2. The sea was rough and the waves were high.
3. The Mediterranean sea is known for its clear blue waters and sandy beaches.