[ toh-nom-i-ter ]
/ toʊˈnɒm ɪ tər /


an instrument for measuring the frequencies of tones, as a tuning fork or a graduated set of tuning forks.
any of various physiological instruments for measuring intraocular pressure or blood pressure.
Physical Chemistry. an instrument for measuring vapor pressure.

Nearby words

  1. tonoclonic spasm,
  2. tonofibril,
  3. tonofilament,
  4. tonograph,
  5. tonography,
  6. tonometric,
  7. tonoplast,
  8. tonotopic,
  9. tonotropic,
  10. tons

Origin of tonometer

First recorded in 1715–25; tono- + -meter

Related formston·o·met·ric [ton-uh-me-trik, toh-nuh-] /ˌtɒn əˈmɛ trɪk, ˌtoʊ nə-/, adjectiveto·nom·e·try, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for tonometer

  • The (Schiotz) tonometer was used daily for 70 consecutive days and never registered more than 12-14 mm.


British Dictionary definitions for tonometer


/ (təʊˈnɒmɪtə) /


an instrument for measuring the pitch of a sound, esp one consisting of a set of tuning forks
any of various types of instrument for measuring pressure or tension, such as the blood pressure, vapour pressure, etc
Derived Formstonometric (ˌtɒnəˈmɛtrɪk, ˌtəʊ-), adjectivetonometry, noun

Word Origin for tonometer

C18: from Greek tonos tone + -meter

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for tonometer


[ tō-nŏmĭ-tər ]


Any of various instruments for measuring pressure or tension, especially one used in tonography.
Related formsto′no•metric (tō′nə-mĕtrĭk)•nome•try n.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.