DOOR

noun

1. A portal of entry into a building, room, or vehicle, 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. Any flap, etc. that opens like a door.
3. (immigration) An entry point.

verb

1. To cause a collision by opening the door of a vehicle in front of an oncoming cyclist or pedestrian.