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

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

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

She also bumped her thermostat up to 75, from 70, and plans to use fans more often as the weather warms.

From The Wall Street Journal ● Mar. 25, 2026

She lets the water run in the shower, turns up the thermostat to compensate for the terrible moment when she will have to step onto the mat on the bathroom floor, unclothed.

From "The Namesake" by Jhumpa Lahiri

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

“Closing vents or cranking thermostats too quickly to cool or heat your home only uses more energy and creates an imbalance.”

From MarketWatch ● Nov. 10, 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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