attenuation

UK: /əˌtenjʊˈeɪʃən/ US: (ə ten′yo̅o̅ ā′shən)

WordReference Random House Unabridged Dictionary of American English © 2026

at•ten•u•a•tion  (ə ten′yo̅o̅ ā′shən), n. 

1. the act of attenuating or the state of being attenuated.
2. Microbiology the process by which a virus, bacterium, etc., changes under laboratory conditions to become harmless or less virulent.
3. 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.

• Latin attenuātiōn- (stem of attenuātiō). See attenuate, -ion
• Middle French)
• (1585–95

Collins Concise English Dictionary © HarperCollins Publishers::

attenuation / əˌtɛnjʊˈeɪʃən/ noun

1. the act of attenuating or the state of being attenuated
2. the loss of energy suffered by radiation as it passes through matter, esp as a result of absorption or scattering