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
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To support long-term development, Pulsar is also working with the UK Atomic Energy Authority to study how neutron radiation affects reactor materials. Neetika Walter, Interesting Engineering, 26 Mar. 2026 Deuterium, a stable and non-radioactive isotope of hydrogen that features a neutron in addition to the single proton in its core, is extremely abundant across the universe. Victor Tangermann, Futurism, 25 Mar. 2026 Northwestern and Fermilab are leading an experiment to determine how detectors respond to interactions with known particles — specifically neutrons from a neutron beam — to simulate how the detectors might interact with dark matter particles in the SuperCDMS. Adam Harrington, CBS News, 17 Mar. 2026 The gravitational pressure could be so extreme as to crush neutrons into their building blocks, which are fundamental particles called quarks and the gluons that ordinarily bind quarks together to form protons and neutrons. Keith Cooper, Space.com, 15 Mar. 2026 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 1 Apr. 2026.

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

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