IPA: /ˈlɛtəˌbɒks/
KK: /ˈlɛtərˌbɑks/
A box, usually mounted on a wall or post, where letters and packages are delivered by the mail carrier.
I checked the letterbox for any mail after returning home.
To present a film in a specific format that shows black bars at the top and bottom of the screen, making the image wider.
The director decided to letterbox the movie to give it a more cinematic look.
Past: letterboxed
Past Participle: letterboxed
Letterbox → It is formed from "letter" (from Old English *letra*, meaning a written character or symbol) and "box" (from Old English *box*, meaning a container). The word "letterbox" refers to a container for receiving letters or mail.
Think of a 'container' ('box') that holds 'written characters' ('letter') — that's what a letterbox is for.
No commonly confused words.