doorsensor
nounUK /ˈdɔːˌsɛnsə/
US /ˈdɔːrˌsɛnsər/
A small device that tells you when a door opens or closes.
The door sensor beeped when I opened the back door.
RELATED WORDS
OTHER MEANINGS
2. A part in a car that notices when a door is not shut.
The car's door sensor warned us that a door was open.
3. A gadget that turns on lights when someone walks through a doorway.
The door sensor switched on the hallway light.
4. A safety device on a machine that stops it if a door is opened.
The door sensor shut off the machine when the panel opened.