A basement is the floor of a building that sits partially or completely below ground level. Most houses with basements have stairs leading down from the main floor to this underground space, which often stays naturally cool because it's surrounded by earth.

Basements serve different purposes depending on the family. Some people use them for storage, keeping holiday decorations, old furniture, or boxes of memories tucked away where they won't clutter the main house. Others finish their basements with carpet, drywall, and lighting to create extra living space: a playroom, home office, or guest bedroom. Many basements house important equipment like furnaces, water heaters, and washing machines.

Because basements sit below ground, they can flood during heavy rains if water seeps through the foundation or if gutters don't direct rainwater away from the house properly. This is why you'll often see sump pumps in basements, ready to pump out water that accumulates.

The word also appears in phrases like bargain basement, which refers to deeply discounted goods.