What is the meaning of door?

noun

• A swinging or sliding barrier that will close the entrance to a room or building or vehicle.
  • usage: "he knocked on the door"; "he slammed the door as he left"
• The entrance (the space in a wall) through which you enter or leave a room or building; the space that a door can close.
  • usage: "he stuck his head in the doorway"
  • synonyms: doorway, room access, threshold
• Anything providing a means of access (or escape. )
  • usage: "we closed the door to Haitian immigrants"; "education is the door to success"
• A structure where people live or work (usually ordered along a street or road. )
  • usage: "the office next door"; "they live two doors up the street from us"
• A room that is entered via a door.
  • usage: "his office is the third door down the hall on the left"