thermostat

American  

[thur-muh-stat] / ˈθɜr məˌstæt /

noun

1. a device, including a relay actuated by thermal conduction or convection, that functions to establish and maintain a desired temperature automatically or signals a change in temperature for manual adjustment.

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verb (used with object)

thermostatted, thermostated, thermostatting, thermostating

1. to equip or control with a thermostat.

thermostat British  

/ ˈθɜːməˌstæt /

noun

1. a device that maintains a system at a constant temperature. It often consists of a bimetallic strip that bends as it expands and contracts with temperature, thus breaking and making contact with an electrical power supply

2. a similar device that actuates equipment, such as a sprinkler, when a certain temperature is reached

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thermostat Scientific  

/ thûr′mə-stăt′ /

1. A device that automatically controls heating or cooling equipment in such a way as to maintain a temperature at a constant level or within a specified range, generally using a thermometer capable of triggering electrical switches that activate or deactivate the equipment.

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thermostat Cultural  

1. A device that monitors and automatically responds to changes in temperature and activates switches controlling devices such as furnaces or air conditioners.

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Other Word Forms

• thermostatic adjective
• thermostatically adverb

Etymology

Origin of thermostat

First recorded in 1825–35; thermo- + -stat

Example Sentences

Though Americans crank up the thermostat every winter, price increases for electricity and gas utility bills were not as sharp at the same point last year.

From MarketWatch • Feb. 13, 2026

As the child of penny-pinching Sicilian parents, I’m all too familiar with the dread surrounding the thermostat come midwinter.

From The Wall Street Journal • Jan. 23, 2026

Madeline Marchiano realizes that this winter’s runaway heating prices mean she can’t afford to raise her thermostat enough to warm her entire South Philadelphia rowhouse.

From Barron's • Jan. 22, 2026

And it means that body weight is like a thermostat: your body aims to maintain that preferred range.

From BBC • Jan. 4, 2026

The thermostat was turned all the way up and the furnace was banging and sounding like it was about to blow up but it still felt like Jack Frost had moved in with us.

From "The Watsons Go to Birmingham" by Christopher Paul Curtis

Related Words

• manager