A shelf is a flat, horizontal surface attached to a wall or built into furniture, designed to hold and display objects. Walk into any room and you'll likely spot shelves: in bookcases holding novels and textbooks, in kitchens supporting plates and cereal boxes, in bathrooms storing towels and toothpaste.

Shelves keep things organized and accessible. Instead of stacking books in piles on the floor, you arrange them on shelves where you can see their spines and grab the one you want. Libraries have thousands of shelves, each labeled so people can find exactly what they're looking for.

The word also appears in useful phrases. When something gets put on the shelf, it means a plan or project gets postponed or set aside, like when your family puts vacation plans on the shelf because someone gets sick. Items sitting in stores waiting to be purchased are on the shelves, and when stores run out of something popular, they say it's flying off the shelves.

The plural is shelves (changing the “f” to “v”).