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nuclei

American  
[noo-klee-ahy, nyoo-] / ˈnu kliˌaɪ, ˈnyu- /

noun

  1. plural of nucleus.


nuclei British  
/ ˈnjuːklɪˌaɪ /

noun

  1. a plural of nucleus

"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

Etymology

Origin of nuclei

< Latin nucleī, nominative plural of nucleus; nucleus

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Fusion does the opposite: It combines light atomic nuclei into heavier ones, releasing enormous energy.

From The Wall Street Journal • Mar. 28, 2026

"These nuclei are hard to make and require a lot of new technology to synthesize in sufficient quantities," Grzywacz explained.

From Science Daily • Mar. 13, 2026

To generate the required beam, scientists accelerated Mo-92 ions and fired them at a beryllium target, producing fast moving Mo-86 nuclei.

From Science Daily • Mar. 8, 2026

During this step, some nuclei became excited, while others lost two neutrons and transformed into Mo-84.

From Science Daily • Mar. 8, 2026

Why, as Arthur Eddington liked to ask, do the nuclei that comprise my elbow not slide effortlessly through the nuclei that comprise the table?

From "Cosmos" by Carl Sagan