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

What to set your thermostat to in winter The Department of Energy's recommendation is to set your thermometer to 68 degrees during the winter. —Iris Seaton, The Providence Journal, 23 Jan. 2026

If geopolitics had a thermometer, the mercury would have dropped by a couple of degrees over the past 48 hours. —Eleanor Pringle, Fortune, 23 Jan. 2026

Temperatures on Friday are expected to rise no higher than 15 degrees in Denver, with the thermometer dipping to a few notches above zero tonight. —John Aguilar, Denver Post, 23 Jan. 2026

That day the thermometer sank to minus 25, tying the record for the city's coldest-ever temperature. —Steven Martinez, jsonline.com, 21 Jan. 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