# plethysmograph

> English word · Noun · IPA /plɛˈðɪz.məˌɡɹæf/

## Definitions
1. An instrument for measuring changes in volume within an organ or whole body (usually via fluctuations in the amount of fluid it contains).

## Etymology
Late 19th century: from Ancient Greek πληθυσμός (plēthusmós, “enlargement”) + -graph.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/plethysmograph