billboard

1. (dated) A flat surface, such as a panel or fence, on which bills are posted; a bulletin board.Examples: "When a show leaves New York, it carries posters wherewith to embellish each fence and bill board in the land [...]"; "Toward the end of April, the billboards, which I watched anxiously in those days, bloomed out one morning with gleaming white posters on which two names were impressively printed in blue Gothic letters: the name of an actress of whom I had often heard, and the name “Camille.”"; "Until the recent rash of North London line maps appeared on station billboards in the London area of BR, the service undoubtedly suffered from meagre and ineffectual publicity."dated

2. (nautical) A piece of thick plank, armed with iron plates, and fixed on the bow or fore-channels of a vessel, for the bill or fluke of the anchor to rest on.

3. (television, radio) An opening or closing portion of a program, often including credits and sponsors' names.Examples: "The closing billboard features Como as the spokesman."; "[…] the opening billboard identifying Chase as the sponsor […]"

4. (computer graphics) A sprite that always faces the screen, no matter which direction it is viewed from.