Bay refers to a body of water that curves into the coastline, creating a partly enclosed area where the ocean or a large lake meets the land. Picture a gentle bite taken out of a shoreline. Bays are usually calmer than the open ocean because the surrounding land protects them from strong winds and waves.

Many important cities developed around bays because they provided natural harbors where ships could anchor safely. San Francisco Bay, Chesapeake Bay, and Hudson Bay are famous examples. Fishermen often work in bays because fish gather in these sheltered waters. Swimming, sailing, and watching wildlife are popular bay activities.

The word also appears in expressions like keeping someone at bay, which means holding them off or preventing them from getting too close, like a cornered animal keeping predators at bay.

In architecture, a bay window is a window that sticks out from the wall of a building, creating a small alcove inside.

As an adjective, bay describes a reddish-brown color, especially when talking about horses. A bay horse has a brown body with a black mane and tail.

As a noun, bay can also mean the long, loud howl of a wolf or dog.