at·​ten·​u·​a·​tion | \ ə-ˌten-yə-ˈwā-shən How to pronounce attenuation (audio) , -yü-ˈā- \
plural attenuations

Definition of attenuation

: the act or process of attenuating something or the state of being attenuated: such as
a : a lessening in amount, force, magnitude, or value : weakening Sound can travel thousands of kilometers in this planar acoustic waveguide with little attenuation.— David Ritchie
b : a reduction of severity or virulence : a decrease in the pathogenicity of a microorganism or in the severity of a disease This virus grew well in tissue culture, with only limited temperature sensitivity as a marker of possible attenuation.— Peter F. Wright
c : diminution of thickness The detailing of the doorway, the narrowness and attenuation of the columns of the portico, and most especially the paneling and ornamentation in the interior … bespeak the neoclassical, somewhat similar to the plaster work found in Baltimore interiors.— Jessie Poesch

First Known Use of attenuation

1559, in the meaning defined above

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Time Traveler for attenuation

Time Traveler

The first known use of attenuation was in 1559

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Cite this Entry

“Attenuation.” Dictionary, Merriam-Webster, Accessed 8 Aug. 2020.

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at·​ten·​u·​a·​tion | \ ə-ˌten-yə-ˈwā-shən How to pronounce attenuation (audio) \

Medical Definition of attenuation

: a decrease in the pathogenicity or vitality of a microorganism or in the severity of a disease


at·​ten·​u·​a·​tion | \ ə-ˌten-yu̇-ˈwā-shən How to pronounce attenuation (audio) \

Legal Definition of attenuation

: a lessening of the amount, force, or magnitude of something specifically : a weakening of the connection between an illegal police procedure and the evidence obtained by it such that the evidence is admissible at trial as an exception to the exclusionary rule

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