Try Our Apps


Avoid these words. Seriously.


[uh-ten-yoo-ey-shuh n] /əˌtɛn yuˈeɪ ʃən/
the act of attenuating or the state of being attenuated.
the process by which a virus, bacterium, etc., changes under laboratory conditions to become harmless or less virulent.
Physics. a decrease in a property, as energy, per unit area of a wave or a beam of particles, occurring as the distance from the source increases as a result of absorption, scattering, spreading in three dimensions, etc.
Origin of attenuation
1585-95; (< Middle French) < Latin attenuātiōn- (stem of attenuātiō). See attenuate, -ion
Related forms
subattenuation, noun Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
Cite This Source
Examples from the Web for attenuation
Historical Examples
British Dictionary definitions for attenuation


the act of attenuating or the state of being attenuated
the loss of energy suffered by radiation as it passes through matter, esp as a result of absorption or scattering
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
Cite This Source
Word Origin and History for attenuation

early 15c., of persons, "emaciation;" of diet, "reduction," from Latin attenuationem (nominative attenuatio) "a lessening," noun of action from past participle stem of attenuare (see attenuate).

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
attenuation in Medicine

attenuation at·ten·u·a·tion (ə-těn'yōō-ā'shən)

  1. A dilution, thinning, or weakening of a substance, especially a reduction in the virulence of a pathogen through repeated inoculation, growth in a different culture medium, or exposure to heat, light, air or other weakening agents.

  2. The energy loss of an ultrasonic beam as it passes through a material.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source

Word of the Day

Nearby words for attenuation

Word Value for attenuation

Scrabble Words With Friends