This is the 3435th most frequent Japanese word.
点灯
"点灯" means "turning on a light" or "lighting up."
In this sentence, "点灯" refers to the action of turning on the room's lighting.
部屋の点灯が自動で行われます。
The lighting in the room is automatically turned on.
Here, "点灯" is used as a command to turn on the outdoor lights.
外のライトを点灯してください。
Please turn on the outside lights.
In this context, "点灯" describes the status of the traffic signal being illuminated in red.