detector
nounUK /dɪˈtektə/
US /dɪˈtektər/
A detector is a machine that finds things like smoke or metal.
The smoke detector beeped loudly when the toast burned.
OTHER MEANINGS
2. A device that senses smoke and warns people of fire.
We changed the batteries in the smoke detector.
3. A device that finds metal objects hidden in the ground.
He used a metal detector at the beach.
4. A person or thing that discovers something.
She is a good detector of lies.