Origin: Greek prefix thermo-
Thermostat has 3 different meanings across 2 categories:
a regulator for automatically regulating temperature by starting or stopping the supply of heat
"The old thermostat in our boiler room is stuck, so it refuses to start the heating even though the house has frozen."
A device that automatically responds to changes in temperature by activating a heating or cooling system to maintain the temperature at a desired setting.
"After I installed the new thermostat, my house stayed at exactly seventy degrees even when the outside weather turned freezing hot."
control the temperature with a thermostat
"We need to adjust the thermostat because it is too cold in the living room."