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

Example Sentences

Recent Examples on the Web 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

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'tonometer.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


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

Dictionary Entries Near tonometer

Cite this Entry

“Tonometer.” Dictionary, Merriam-Webster, Accessed 31 Jan. 2023.

Medical Definition


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

More from Merriam-Webster on tonometer

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