An entry point.
A barrier.
A means of approach or access.
A portal of entry into a building, room, or vehicle, typically 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.
Any flap, etc. that opens like a door.
A possibility.
The proceeds from entrance fees and/or ticket sales at a venue such as a bar or nightclub, especially in relation to portion paid to the entertainers. "The bar owner gives each band a percentage of the door and charges customers more to get in"
To cause a collision by opening the door of a vehicle in front of an oncoming cyclist or pedestrian.
A machine that moves breathable air into and out of the lungs of a patient who is unable to breathe sufficiently.
A device that circulates fresh air and expels stale or noxious air.
Some behaviour or happening that relieves a tense atmosphere or situation.