a shadowy, indefinite, or marginal area: a penumbra of secrecy.
U.S. Law. a right or set of rights implicit but not expressed in the U.S. Constitution or Bill of Rights: The principle of the penumbra protects against an imperfect, or incomplete, enumeration of rights.
- pe·num·bral, pe·num·brous, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use penumbra in a sentence
Yes, both injuries are experienced during a traumatic event; however, the psychological penumbra is very different.Study Says Half of Jailed NYC Teens Have History of Brain Injury | Dr. Anand Veeravagu, MD, Tej Azad | April 22, 2014 | THE DAILY BEAST
In person, Waltz is equally charming, but without the penumbra of menace that comes with having Nazi goons just outside the door.
It formed, as it were, a penumbra of fine shrilling, and could be heard for many streets in advance.The Dragon Painter | Mary McNeil Fenollosa
The penumbra will last quite a long time yet, but it will gradually get fainter and fainter.Pharaoh's Broker | Ellsworth Douglass
And the concert ended, and soon they were alone together in the flower-filled, fragrant penumbra of the moving carriage.The Devourers | Annie Vivanti Chartres
He has touched even the dark penumbra of treason; that could not but risk the sum of his other strivings.The Posthumous Works of Thomas De Quincey, Vol. 1 (2 vols) | Thomas De Quincey
This portion was the kernel of the inheritance, surrounded by a wide penumbra of more feeble light and fewer privileges.The Expositor's Bible: The Book of Joshua | William Garden Blaikie
British Dictionary definitions for penumbra
a fringe region of half shadow resulting from the partial obstruction of light by an opaque object
astronomy the lighter and outer region of a sunspot
painting the point or area in which light and shade blend
- Compare umbra
- penumbral or penumbrous, adjective
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
Scientific definitions for penumbra
A partial shadow between regions of full shadow (the umbra) and full illumination, especially as cast by Earth, the Moon, or another body during an eclipse. During a partial lunar eclipse, a portion of the Moon's disk remains within the penumbra of Earth's shadow while the rest is darkened by the umbra. See Note at eclipse.
The grayish outer part of a sunspot. Compare umbra.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.