thermometer

noun

ther·​mom·​e·​ter thər-ˈmä-mə-tər 

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

thermometric

ˌthər-mə-ˈme-trik 

adjective

thermometrically

ˌthər-mə-ˈme-tri-k(ə-)lē 

adverb

Examples of thermometer in a Sentence

Recent Examples on the Web

Test outdoor garden soil with a digital thermometer or wait until air temperatures remain above 75°F for at least three days and nights. —Barbara Gillette, The Spruce, 20 Apr. 2026

Use a food thermometer to check the temperature. —Lisa Cericola, Southern Living, 19 Apr. 2026

The public art serves as a visual thermometer that interacts with the weather to highlight the dangers of extreme heat in Massachusetts. —Alyssa Andrews, CBS News, 17 Apr. 2026

Cold weather is expected to linger overnight, with thermometers expected to drop to 18 degrees, according to the National Weather Service. —Katie Langford, Denver Post, 17 Apr. 2026

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

Phrases Containing thermometer

• clinical thermometer
• dry-bulb thermometer
• forehead thermometer
• temporal artery thermometer
• temporal thermometer

Rhymes for thermometer

• barometer
• bolometer
• chronometer
• geometer
• hydrometer
• hygrometer
• kilometer
• micrometer
• odometer
• photometer
• psychrometer
• pycnometer

Kids Definition

thermometer

noun

ther·​mom·​e·​ter thə(r)-ˈmäm-ət-ər 

: an instrument for measuring temperature

thermometric

ˌthər-mə-ˈme-trik 

adjective

Medical Definition

thermometer

noun

ther·​mom·​e·​ter thə(r)-ˈmäm-ət-ər 

: 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