an enclosed passageway; rooms usually open onto it
"The students walked down the long corridor, where their classrooms opened directly onto the tiled walls on either side."
A narrow hall or passage with rooms leading off it, as in a building or in a railway carriage.
"The passengers moved quickly down the narrow corridor between the train carriages to reach their seats."
In plain English: A corridor is an indoor hallway that connects different rooms and lets you walk from one place to another inside a building.
"The emergency exit was located at the end of the long corridor."
Usage: Use "corridor" to describe an enclosed passageway connecting multiple rooms within a single structure like a school or train car. Do not use this word for outdoor walkways or open-air hallways where the term "pathway" is more appropriate.
The word entered English from the French corridor, which originally described a long passageway. This term ultimately traces back to the Italian verb for "to run."