: a very sensitive thermometer whose electrical resistance varies with temperature and which is used in the detection and measurement of feeble thermal radiation and is especially adapted to the study of infrared spectra

Word History

Etymology

Greek bolē stroke, beam of light (from ballein to throw) + English -o- + -meter — more at devil

First Known Use

1878, in the meaning defined above

Time Traveler
The first known use of bolometer was in 1878

Browse Nearby Words

Cite this Entry

“Bolometer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/bolometer. Accessed 7 Jul. 2026.

Medical Definition

bolometer

noun
: a very sensitive thermometer used in the detection and measurement of feeble thermal radiation and especially adapted to the study of infrared spectra

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