tonometer

noun

to·​nom·​e·​ter tō-ˈnä-mə-tər How to pronounce tonometer (audio)
1
: an instrument or device for determining the exact pitch or the vibration rate of tones
2
: an instrument for measuring tension or pressure and especially intraocular pressure
tonometry noun

Examples of tonometer 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 Morgan was wearing the Chibis pants, Meir used a tonometer to measure his eye pressure, with doctors on Earth watching in real time. Ashley Strickland, CNN, 23 Mar. 2020 Today, ophthalmologists measure IOP during eye exams using tools called tonometers, which either send a puff of air into the eye or press a probe against the eye’s numbed surface. IEEE Spectrum, 25 July 2017

Word History

Etymology

Greek tonos tone + English -meter

First Known Use

1725, in the meaning defined at sense 1

Time Traveler
The first known use of tonometer was in 1725

Browse Nearby Words

Cite this Entry

“Tonometer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tonometer. Accessed 10 Sep. 2025.

Medical Definition

tonometer

noun
to·​nom·​e·​ter tō-ˈnäm-ət-ər How to pronounce tonometer (audio)
: an instrument for measuring tension or pressure and especially intraocular pressure
tonometric adjective
tonometry noun
plural tonometries

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