The phrase "adjacent door" is correct and usable in written English.
It can be used to refer to a door that is next to another door, often in the context of describing locations or directions.
Example: "The meeting room is located to the left of the adjacent door, which leads to the storage area."
Alternatives: "next door" or "neighboring door".
The adjacent door was ajar, its frame twisted.
Suddenly the adjacent door opened — it was Ms. Montgomery's sister, Angela.
Unable to face him he turned through an adjacent door to discover himself in a broom cupboard.
A handwritten sign taped to the front door says that the library is closed, and directs people who have come to return books toward a mail slot in an adjacent door.
In a hallway outside of an interview room, Williams slipped inside of a vestibule, where she went unnoticed as Lisa Raymond exited an adjacent door and walked past her.
In another, the animals were placed in front of a clear acrylic box with two small swinging doors that opened only toward the inside; a piece of food was placed on one of two small shelves behind the doors, so that it would fall off if the subject tried to get it via the direct route rather than reaching around through the adjacent door.
Indeed, in these cases, passengers tend to modify the selected door (choosing adjacent doors and/or adjacent coaches) as a function of the crowding degree in order to board as soon as possible.
When in front of a door there is a larger group of passengers than a set value (which, obviously, varies from case to case), they start moving to the adjacent doors in the same coach.
Two adjacent doors will automatically orientate to become double doors.
Nate Freedman, the owner, signed a ten-year lease on his printing shop next door, plus two adjacent storefronts.
Just next door in the adjacent gallery space at Artereal, is Eloise Kirk's The Deepest Cave on Earth, a modest but conceptually rigorous exploration of landscape forms.
