thermostat
//ˈθɜːməʊstæt//
Noun
thermostatSingular
thermostatsPlural
1
A device that automatically regulates temperature by switching heating or cooling equipment on or off to maintain a desired temperature.
I set the thermostat to 22 degrees to keep the room comfortable.
2
A component in an engine cooling system that regulates the flow of coolant to maintain optimal operating temperature.
The mechanic replaced the thermostat because the engine was overheating.