neutron

noun

neu·​tron ˈnü-ˌträn How to pronounce neutron (audio)
ˈnyü-
: an uncharged elementary particle that has a mass nearly equal to that of the proton and is present in all known atomic nuclei except the hydrogen nucleus
neutronic adjective

Examples of neutron in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Beyond electrons, the quarks that make up protons and neutrons in atomic nuclei are also fermions. Matt Von Hippel, Quanta Magazine, 23 June 2025 An atom consists of a heavy center, called the nucleus, made of particles called protons and neutrons. Stephen L. Levy, The Conversation, 23 June 2025 This not only means dark matter is effectively invisible, but also that it can't be composed of particles like electrons, protons, and neutrons that make up the atoms that compose everyday matter like stars, planets, moons, and the cat next door. Robert Lea, Space.com, 17 June 2025 But the rest of the universe is made of cosmic baryons, or ordinary matter, which can be found in tiny particles called protons and neutrons. Ashley Strickland, CNN Money, 16 June 2025 See All Example Sentences for neutron

Word History

Etymology

probably from neutral

First Known Use

1921, in the meaning defined above

Time Traveler
The first known use of neutron was in 1921

Cite this Entry

“Neutron.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/neutron. Accessed 30 Jun. 2025.

Kids Definition

neutron

noun
neu·​tron ˈn(y)ü-ˌträn How to pronounce neutron (audio)
: an uncharged atomic particle that has a mass nearly equal to that of the proton and is present in all known atomic nuclei except the hydrogen nucleus

Medical Definition

neutron

noun
neu·​tron ˈn(y)ü-ˌträn How to pronounce neutron (audio)
: an uncharged elementary particle that has a mass nearly equal to that of the proton and is present in all known atomic nuclei except the hydrogen nucleus

More from Merriam-Webster on neutron

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