letterbox

Imagine a small opening in a front door, just wide enough for letters to slip through. That is a letterbox. In British English, the word can mean the slot in a door or a box outside a house where the post is delivered. In American English, people usually say "mailbox" instead. It keeps letters in one place and helps protect them from rain and wind.

You might see one built into a door, fixed to a wall, or standing by the road. The word is also used in film and television. When a wide movie is shown on a narrower screen without cutting off the sides, black bars appear at the top and bottom. This is called letterboxing because the picture looks a bit like the shape of a narrow mail slot.

A letterbox is an opening or container used for receiving mail. In British English, it often means the slot in a front door that letters are pushed through, but it can also mean a box outside the home for incoming post. In North American English, the usual word is "mailbox." Historically, letterboxes were often simple slots cut into wooden doors, but modern ones may be built from metal, plastic, or other sturdy materials. Their basic job is to give the postal worker an easy place to leave mail while helping to protect it from weather and casual theft.

The word is strongly tied to everyday home life, because it is part of how messages, bills, postcards, and small printed items arrive. Depending on the house and the country, you may find a letterbox in the door, on a gate, on a wall, or at the edge of a driveway. In many places, people speak of "checking the letterbox" as part of an ordinary daily routine.

The word also appears in film and television. In this sense, letterboxing is the showing of a wide picture on a narrower screen while keeping the full width of the image. This leaves black bars at the top and bottom. The name comes from the long, narrow shape, which suggests the slot of a traditional letterbox. So the word can refer either to a place where mail is delivered or, in visual media, to a way of showing a wide image without cutting off the sides.