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eta-c meson

American  
[ey-tuh-see, ee-tuh-] / ˈeɪ təˈsi, ˈi tə- /

noun

Physics.

  1. a neutral meson having a mass 5832 times that of the electron and a mean lifetime of approximately 3.1 × 10 -22 seconds.

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.

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