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letterbox

American  
[let-er-boks] / ˈlɛt ərˌbɒks /

noun

  1. Chiefly British. Also letter box 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.


verb (used with object)

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

Etymology

Origin of letterbox

First recorded in 1765–75; letter 1 ( def. ) + box 1 ( def. )