nu·​cle·​on | \ ˈnü-klē-ˌän How to pronounce nucleon (audio) , ˈnyü-\

Definition of nucleon

1 : a proton or neutron especially in the atomic nucleus
2 : a hypothetical single entity with one-half unit of isospin that can manifest itself as either a proton or a neutron

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Other Words from nucleon

nucleonic \ ˌnü-​klē-​ˈä-​nik How to pronounce nucleonic (audio) , ˌnyü-​ \ adjective

Examples of nucleon in a Sentence

Recent Examples on the Web

Atomic nuclei are made of protons and neutrons, known collectively as nucleons. The Economist, "Who did the Maya sacrifice?," 1 Aug. 2019 Her model explained why certain numbers of nucleons make for stable atomic configurations. Jill Kiedaisch, Popular Mechanics, "32 Women Who’ve Changed Life As We Know It," 31 Mar. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'nucleon.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of nucleon

1923, in the meaning defined at sense 1

History and Etymology for nucleon

International Scientific Vocabulary

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Statistics for nucleon

Last Updated

13 Aug 2019

Look-up Popularity

Time Traveler for nucleon

The first known use of nucleon was in 1923

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More Definitions for nucleon


nu·​cle·​on | \ ˈn(y)ü-klē-ˌän How to pronounce nucleon (audio) \

Medical Definition of nucleon

: a nuclear particle:
a : proton
b : neutron

Other Words from nucleon

nucleonic \ ˌn(y)ü-​klē-​ˈän-​ik How to pronounce nucleonic (audio) \ adjective

More from Merriam-Webster on nucleon

Rhyming Dictionary: Words that rhyme with nucleon Encyclopedia article about nucleon

Comments on nucleon

What made you want to look up nucleon? Please tell us where you read or heard it (including the quote, if possible).


authorized for issue (as a bond)

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