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.

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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

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

"Raise your thermostat as high as is comfortably safe," the company urged, while calling on residents to delay using laundry, dishwashers and electric vehicle chargers until after 8:00 pm.

From Barron's ● Jul. 1, 2026

Deploy fans: Ceiling fans create a wind-chill effect that makes a room feel several degrees cooler, allowing you to set the thermostat higher.

From MarketWatch ● Jun. 29, 2026

Gavin says he's happy to have the house at 19C or 20C but his wife sometimes turns up the thermostat to 23C.

From BBC ● Apr. 15, 2026

“They moved us to a DRU before Thanksgiving, so we’re okay. Mom complains because they keep the thermostat at sixty-five. But no one ever froze to death at sixty-five.”

From "The Dead and the Gone" by Susan Beth Pfeffer

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

Under the agreement, Voltus will pay homes and businesses to reduce power consumption during times of peak demand and make use of technology including home batteries and smart thermostats to manage that.

From The Wall Street Journal ● Jun. 3, 2026

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

In his first televised fireside chat, he wore a cardigan sweater and encouraged Americans to conserve energy during the winter by keeping their thermostats at 65 degrees in the daytime and 55 degrees at night.

From Los Angeles Times ● Dec. 29, 2024

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

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