billboard

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A panel for the display of advertisements in public places, such as alongside highways or on the sides of buildings.
2. n. The advertisement or message posted on such a panel.
3. n. An introductory list of highlights from the program or text that follows, as in a broadcast or magazine.
4. v. To advertise or proclaim on or as if on a billboard: billboarded as the workers' candidate.
5. n. Nautical A ledge on the bow of a ship on which the bill of an anchor rests when the anchor is secured to the cathead.

Century Dictionary and Cyclopedia

1. n. Nautical, a projection sheathed with iron placed abaft the cathead, for the bill of the anchor to rest on. See anchor-lining.
2. n. A board or tablet on which advertising bills or placards may be posted.
3. n. A ticket of admission to a theatrical performance, circus, or the like, given to shopkeepers, etc., in return for billboard privileges accorded.

Wiktionary

1. n. A very large advertisement along the side of a highway.
2. n. dated A flat surface, such as a panel or fence, on which bills are posted; a bulletin board.
3. n. 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.
4. n. computer graphics A sprite that always faces the screen, no matter which direction it's looked at from.

GNU Webster's 1913

1. n. (Naut.) 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.
2. n. A flat surface, as of a panel or of a fence, on which bills are posted; a bulletin board. A large board out of doors and visible to passers-by, on which the space is rented for advertising purposes; also, the advertising displayed on such a board.

WordNet 3.0

1. n. large outdoor signboard