thermometer

noun

ther·​mom·​e·​ter thər-ˈmä-mə-tər How to pronounce thermometer (audio)
thə-ˈmä-mə-tər
plural thermometers
: an instrument for determining temperature
specifically : one consisting of a sensor housed in a metal probe that registers a change in electrical resistance as a change in temperature

Examples of thermometer in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
While Las Vegas and Phoenix will be near the core of the triple-digit heat through this week and even beyond, the thermometer will also be hot in places like Denver or Salt Lake City, where the 90s are forecast, AccuWeather said. Doyle Rice, USA Today, 6 July 2026 Monitor Temperature and Water Quality A floating pool thermometer—available for around $10—tells you if your pond is getting too hot. Anne Readel, Better Homes & Gardens, 6 July 2026 For an even more precise read on the internal temperature of your coolers, Just suggests investing in an instant-read thermometer. Alyssa Modos, PEOPLE, 4 July 2026 On the field between home plate and first base, a thermometer read nearly 97 degrees before the game. Eva Andersen, CBS News, 2 July 2026 See All Example Sentences for thermometer

Word History

Etymology

French thermomètre, from Greek thermē heat + French -o- + -mètre -meter — more at therm

First Known Use

1633, in the meaning defined above

Time Traveler
The first known use of thermometer was in 1633

Cite this Entry

“Thermometer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/thermometer. Accessed 10 Jul. 2026.

Kids Definition

thermometer

noun
: an instrument for measuring temperature

Medical Definition

thermometer

noun
: an instrument for determining temperature that usually consists either of a device providing a digital readout or of a glass bulb attached to a fine tube of glass with a numbered scale and containing a liquid (as mercury or colored alcohol) that is sealed in and rises and falls with changes of temperature

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