What is the meaning of the word "door"?

Definitions:

a room that is entered via a door noun
- My office is the third door down the hall on the left.
a structure where people live or work, usually ordered along a street or road noun
- We often go to lunch with the workers from the office next door.
a swinging or sliding barrier that will close the entrance to a room or building or vehicle noun
- I knocked on the door.
anything providing a means of access (or escape) noun
- we closed the door to Haitian immigrants
the entrance (the space in a wall) through which you enter or leave a room or building noun
- the space that a door can close