/ Dictionary / Index P plethysmograph: Meaning and Definition of Find definitions for: ple•thys•mo•graph Pronunciation: (plu-thiz'mu-graf", -gräf"), [key] — n. a device for measuring and recording changes in the volume of the body or of a body part or organ. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: plethysmograph (Thesaurus) plethysmogram pleur- Related Content Daily Word Quiz: fervor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language