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

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

Money saving is already ingrained at home, with batch cooking, more prudent selections on the thermostat, and warming the body rather than the whole home having become the norm for many people.

From BBC • Jan. 23, 2026

“That doesn’t look like it’ll go away anytime soon. People are going to be heavy on the thermostat for a good two weeks,” he said.

From MarketWatch • Jan. 22, 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

There’s a little piece of tape over the thermostat, a reminder for me and Sam not to touch it.

From "Free Lunch" by Rex Ogle

Related Words

• manager