letterboxing

noun

1. Also letter box. Chiefly British. a public or private mailbox.
2. Digital Technology, Television. a technique for displaying a wide-screen film or landscape video on a narrower screen by reducing its size but retaining the aspect ratio, with black bands filling the screen above and below the picture (often used attributively):letterbox videos.Compare pan and scan, pillarbox(def 1).

verb (used with object)

3. Digital Technology, Television. to display (a film or video) by using the letterbox technique.

noun

1. a method of formatting film that enables all of a wide-screen film to be transmitted on a television screen, resulting in a blank strip of screen above and below the picture
2. a type of treasure hunt in which a box, known as a letterbox, is hidden in a remote rural location and clues are provided as to its whereabouts