thermostat

American  

[thur-muh-stat] / ˈθɜr məˌstæt /

noun

• thermostats
  plural

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.

---

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

---

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.

---

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.

---

Other Word Forms

Derived Forms

• thermostatic
  adjective
• thermostatically
  adverb

Inflected Forms

Nouns

• thermostats
  plural

Etymology

Origin of thermostat

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

Explanation

If your house is always too cold in the winter, you might need to adjust the thermostat, or the dial that controls the indoor temperature. Most devices that emit heat have a thermostat, which controls how hot or cold things get. Car engines, electric blankets, furnaces, and ovens are all equipped with thermostats so that people can change the temperature, or in the case of cars, so that the car itself can keep the engine at the ideal temperature. The noun thermostat comes from the Greek word for heat, thermos, plus statos, or "a standing."

Example Sentences

See Examples For:

thermostat thermostats thermostated

During the World Cup, I was able to upgrade the AC unit, added a smart thermostat and invested in landscaping, which we want to do more of.

From Los Angeles Times ● Jul. 23, 2026

In the winter, Elaine rarely turns the heating on, and when she does she keeps the thermostat at a low 13C.

From BBC ● Jul. 21, 2026

On Thursday, Chicago utility company ComEd said its power grid was under "critical strain," and urged residents to "raise your thermostat as high as is comfortably safe."

From Barron's ● Jul. 3, 2026

Or, use a smart thermostat: A programmable or smart thermostat automates the heavy lifting, raising temperatures when you’re at work and dropping them right before you walk through the door.

From MarketWatch ● Jun. 29, 2026

I didn’t want to say anything to show how impressed I was, but for many nights afterward, I dreamed that we had a thermostat at 93 Little Hobart Street.

From "The Glass Castle" by Jeannette Walls

The companies are forming a power plant that would draw power from Sunrun and Tesla home battery systems and Renew smart thermostats.

From Barron's ● Jun. 24, 2026

Utilities in the Midwest on Saturday directed customers to lower thermostats, unplug “nonessential appliances,” and reduce temperature settings on electric water heaters.

From The Wall Street Journal ● Jan. 25, 2026

Some wireless thermostats are connected to the internet and can be turned on remotely.

From BBC ● Nov. 19, 2025

Decentralized infrastructure solutions are available now, such as rooftop solar and energy storage, and distributed energy resources including heat pumps and smart thermostats.

From MarketWatch ● Nov. 5, 2025

The thermally active carbon made from the shells has actuated laboratory thermostats for me for several years.

From Northern Nut Growers Association Report of the Proceedings at the Thirty-Seventh Annual Report Wooster, Ohio, September 3, 4, 5, 1946 by Northern Nut Growers Association

Soon some 450 great paintings were racked on pipeline scaffolds set up in the huge, thermostated hall where Financier Stotesbury once gave concerts for 1,000 guests.

From Time Magazine Archive

Related Words

• manager