[ pluh-thiz-muh-graf, -grahf ]
/ pləˈθɪz məˌgræf, -ˌgrɑf /
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a device for measuring and recording changes in the volume of the body or of a body part or organ.



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Origin of plethysmograph

First recorded in 1870–75; from Greek plēthysm(ós) “increase, multiplication” (plēthý(nein) “to increase,” derivative of plêthos “large number, crowd” + -smos, variant of -mos noun suffix) + -o- + -graph; first coined in Italian as pletismografo

OTHER WORDS FROM plethysmograph

ple·thys·mo·graph·ic [pluh-thiz-muh-graf-ik], /pləˌθɪz məˈgræf ɪk/, adjectivepleth·ys·mog·ra·phy [pleth-iz-mog-ruh-fee], /ˌplɛθ ɪzˈmɒg rə fi/, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

Example sentences from the Web for plethysmograph

  • I think the experimental psychologists called the thing a "plethysmograph."

    The Silent Bullet|Arthur B. Reeve
  • These instruments are the plethysmograph and the hydrosphygmograph.

    Criminal Man|Gina Lombroso-Ferrero

British Dictionary definitions for plethysmograph

/ (pləˈθɪzməˌɡrɑːf, -ˌɡræf, -ˈθɪs-) /


a device for measuring the fluctuations in volume of a bodily organ or part, such as those caused by variations in the amount of blood it contains

Word Origin for plethysmograph

C19: from Greek plēthusmos enlargement + graphein to write
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

Medical definitions for plethysmograph

[ plĕ-thĭzmə-grăf′ ]


An instrument that measures variations in the size of an organ or body part on the basis of the amount of blood passing through or present in the part.

Other words from plethysmograph

ple•thys′mo•graphic adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.