[pluh-thiz-muh-graf, -grahf]


a device for measuring and recording changes in the volume of the body or of a body part or organ.

Origin of plethysmograph

1870–75; < 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 It as pletismografo
Related formsple·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 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for plethysmograph

Historical Examples of plethysmograph

  • These instruments are the plethysmograph and the hydrosphygmograph.

    Criminal Man

    Gina Lombroso-Ferrero

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

    The Silent Bullet

    Arthur B. Reeve

British Dictionary definitions for plethysmograph



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

plethysmograph in Medicine




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