door

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A movable structure used to close off an entrance, typically consisting of a panel that swings on hinges or that slides or rotates.
2. n. A similar part on a piece of furniture or a vehicle.
3. n. A doorway.
4. n. The room or building to which a door belongs: They live three doors down the hall.
5. n. A means of approach or access: looking for the door to success.
6. v. Slang To strike (a passing bicyclist, for example) by suddenly opening a vehicular door.
7. v. To serve as a doorman or doorwoman of (a nightclub, for example).
8. idiom. at (someone's) door As a charge holding someone responsible: You shouldn't lay the blame for the fiasco at her door.
9. idiom. close To refuse to allow for the possibility of: The secretary of state closed the door on future negotiations.
10. idiom. leave the door open To allow for the possibility of: Let's leave the door open for future stylistic changes.
11. idiom. show (someone) the door Informal To eject (someone) from the premises.
12. idiom. show (someone) the door Informal To terminate the employment of; fire.

Century Dictionary and Cyclopedia

1. n. A movable barrier of wood, metal, stone, or other material, consisting sometimes of one piece, but generally of several pieces framed together, commonly placed on hinges, for closing a passage into a building, room, or other inclosure. In antiquity, as in China and other Eastern countries at the present day, doors often swung on pivots projecting into sockets above and below. Modern carpenters' doors are classified in general as batten-doors and panel-doors. Batten-doors are formed of two or more boards placed longitudinally side by side, and held together by two or more transverse rails. Panel-doors are formed of a skeleton framework called a door-frame, of which the openings are filled with pieces of stuff called panels, which are usually cut from thinner boards than the framework. If the panels are wider than they are high, they are called lying panels; if longer than wide, they are called standing panels.
2. n. An opening for passage into or out of a building or any apartment of it, or any inclosure; a doorway.
3. n. Hence—3. An exterior or public entrance-way, or the house or apartment to which it leads.
4. n. Avenue; passage; means of approach or access, or of exit: commonly in figurative uses: as, the door of reconciliation; a door of escape.
5. n. Near to; bordering on; very nearly.
6. n. Hence, figuratively, quite gone; no more to be found; lost; irrelevant.
7. n. Figuratively, to ruin one.

Wiktionary

1. n. A portal of entry into a building or room, consisting of a rigid plane movable on a hinge. Doors are frequently made of wood or metal. May have a handle to help open and close, a latch to hold the door closed, and a lock that ensures the door cannot be opened without the key.
2. n. Any flap, etc. that opens like a door.
3. n. A non-physical entry into the next world, a particular feeling, a company, etc.
4. n. computing, dated A software mechanism by which a user can interact with a program running remotely on a bulletin board system.
5. v. transitive, cycling To cause a collision by opening the door of a vehicle in front of an oncoming cyclist or pedestrian.

GNU Webster's 1913

1. n. An opening in the wall of a house or of an apartment, by which to go in and out; an entrance way.
2. n. The frame or barrier of boards, or other material, usually turning on hinges, by which an entrance way into a house or apartment is closed and opened.
3. n. Passage; means of approach or access.
4. n. An entrance way, but taken in the sense of the house or apartment to which it leads.

WordNet 3.0

1. n. a swinging or sliding barrier that will close the entrance to a room or building or vehicle
2. n. a structure where people live or work (usually ordered along a street or road)
3. n. a room that is entered via a door
4. n. anything providing a means of access (or escape)
5. n. the entrance (the space in a wall) through which you enter or leave a room or building; the space that a door can close