thermostat

1 of 2

noun

ther·​mo·​stat ˈthər-mə-ˌstat How to pronounce thermostat (audio)
: an automatic device for regulating temperature (as by controlling the supply of gas or electricity to a heating apparatus)
also : a similar device for actuating fire alarms or for controlling automatic sprinklers
thermostatic
ˌthər-mə-ˈsta-tik How to pronounce thermostat (audio)
adjective
thermostatically
ˌthər-mə-ˈsta-ti-k(ə-)lē How to pronounce thermostat (audio)
adverb

thermostat

2 of 2

verb

thermostated ˈthər-mə-ˌsta-təd How to pronounce thermostat (audio) also thermostatted; thermostating also thermostatting

transitive verb

: to provide with or control the temperature of by a thermostat

Examples of thermostat in a Sentence

Noun I set the thermostat to 68 degrees.
Recent Examples on the Web
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Noun
Removing walls for an open floor plan changes airflow patterns, and a single thermostat may struggle to keep temperatures consistent across a larger space, sometimes requiring HVAC modifications to stay comfortable. — Lauren Jarvis-Gibson july 30, Miami Herald, 30 July 2026 Small changes to your thermostat, your appliances and even your lightbulbs can add up to hundreds of dollars a year, according to reporting from Consumer Reports, AAA and CBS News. — Lauren Jarvis-Gibson july 29, Sacbee.com, 29 July 2026 In reality, most residential HVAC systems cool at a relatively consistent rate regardless of how low the thermostat is set. — Angelica Leicht, CBS News, 29 July 2026 Internal thermostats help govern the timing of their northward movements. — Vann R. Newkirk Ii, The Atlantic, 28 July 2026 See All Example Sentences for thermostat

Word History

Etymology

Noun

thermo- + -stat

First Known Use

Noun

1831, in the meaning defined above

Verb

1924, in the meaning defined above

Time Traveler
The first known use of thermostat was in 1831

Rhymes for thermostat

See All Rhymes for thermostat

Browse Nearby Words

thermostable
thermostat
thermostatic
See all Nearby Words

Cite this Entry

“Thermostat.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/thermostat. Accessed 1 Aug. 2026.

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Kids Definition

thermostat

noun
ther·​mo·​stat
ˈthər-mə-ˌstat
: a device that automatically controls temperature
thermostatic
ˌthər-mə-ˈstat-ik
adjective
thermostatically
-i-k(ə-)lē
adverb

Medical Definition

thermostat

1 of 2 noun
ther·​mo·​stat ˈthər-mə-ˌstat How to pronounce thermostat (audio)
1
: an automatic device for regulating temperature (as by controlling the supply of gas or electricity to a heating apparatus)
2
: a piece of apparatus (as a constant-temperature chamber) regulated by a thermostat
thermostatic
ˌthər-mə-ˈstat-ik How to pronounce thermostat (audio)
adjective
thermostatically
-i-k(ə-)lē How to pronounce thermostat (audio)
adverb

thermostat

2 of 2 transitive verb
thermostated -ˌstat-əd How to pronounce thermostat (audio) or thermostatted; thermostating or thermostatting
: to provide with or control the temperature of by a thermostat
a thermostated centrifuge

More from Merriam-Webster on thermostat

Nglish: Translation of thermostat for Spanish Speakers

Britannica.com: Encyclopedia article about thermostat

Last Updated: - Updated example sentences
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