Dictionary.com
Thesaurus.com

Crookes radiometer

American  

noun

Optics.

  1. radiometer.

Crookes radiometer British  

noun

  1. physics a type of radiometer consisting of an evacuated glass bulb containing a set of lightweight vanes, each blackened on one side. The vanes are mounted on a vertical axis and revolve when light, or other radiant energy, falls on them

"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

Etymology

Origin of Crookes radiometer

First recorded in 1880–85; after Sir W. Crookes

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.