thermometer

American  

[ther-mom-i-ter] / θərˈmɒm ɪ tər /

noun

• thermometers
  plural

1. an instrument for measuring temperature, often a sealed glass tube that contains a column of liquid, as mercury, that expands and contracts, or rises and falls, with temperature changes, the temperature being read where the top of the column coincides with a calibrated scale marked on the tube or its frame.

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thermometer British  

/ θəˈmɒmɪtə /

noun

1. an instrument used to measure temperature, esp one in which a thin column of liquid, such as mercury, expands and contracts within a graduated sealed tube See also clinical thermometer gas thermometer resistance thermometer thermocouple pyrometer

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thermometer Scientific  

/ thər-mŏm′ĭ-tər /

1. An instrument used to measure temperature. There are many types of thermometers; the most common consist of a closed, graduated glass tube in which a liquid expands or contracts as the temperature increases or decreases. Other types of thermometers work by detecting changes in the volume or pressure of an enclosed gas or by registering thermoelectric changes in a conductor (such as a thermistor or thermocouple).

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Other Word Forms

Derived Forms

• thermometric
  adjective
• thermometrical
  adjective
• thermometrically
  adverb

Inflected Forms

Nouns

• thermometers
  plural

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Etymology

Origin of thermometer

First recorded in 1615–25; thermo- + -meter

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Explanation

A thermometer is a tool that measures temperature — how hot or cold something is. Thermometers are used to see if you have a fever or tell you how cold it is outside. Made up of thermo (heat) and meter (measuring device), the meaning of the word thermometer is pretty straightforward. Thermometers measure temperatures in degrees, according to either the Celsius or Fahrenheit system. Meteorologists use thermometers to find out how hot it is or if it's below freezing. Doctors use thermometers to check your body temperature — a very high or low body temperature means you're sick.

Example Sentences

See Examples For:

thermometer thermometers

The wind will also make it feel colder than the thermometer suggests, particularly around eastern coastal areas.

From BBC ● Oct. 6, 2026

"Now we have empirical evidence using this geologic thermometer," Chiarenza said.

From Science Daily ● Sep. 20, 2026

By Wednesday, the thermometer could hit 105 degrees in Lancaster, 103 in Canoga Park, 98 in Santa Clarita, 95 in Covina, 89 in downtown L.A.,

From Los Angeles Times ● Jul. 20, 2026

The number on the thermometer isn’t the only thing to worry about this week.

From The Wall Street Journal ● Jul. 2, 2026

The thermometer registered a half degree lower than his usual subnormal temperature of 96.8.

From "Catch-22" by Joseph Heller

Even at sea, thermometers have registered record temperatures.

From Barron's ● Aug. 25, 2026

Today, gallium is widely used in semiconductors, telecommunications equipment, LEDs, laser diodes, solar panels, high performance computing, the aerospace and defense industries, and as a safer alternative to mercury in thermometers.

From Science Daily ● Jul. 9, 2026

One worker said: "We don't seem to have enough thermometers."

From BBC ● Jun. 16, 2026

Two people in the area fainted as thermometers showed the temperature hitting 97 degrees.

From The Wall Street Journal ● Nov. 21, 2025

These army thermometers are not made for old soldiers.

From "All Quiet on the Western Front: A Novel" by Erich Maria Remarque

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Related Words

• instrument
• thermostat

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