neutron

noun

neu·​tron ˈnü-ˌträn 

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

nü-ˈträ-nik 

nyü-

adjective

Examples of neutron in a Sentence

Recent Examples on the Web

Researchers used MedUSA and the same material system to produce neutron sensor brackets for Antares Nuclear’s R1 Mark-0 microreactor, which reached criticality at INL in June. — Aamir Khollam, Interesting Engineering, 21 Aug. 2026

As the cosmos cooled and expanded, the free-floating quarks and gluons started binding together to create the building blocks of all matter, including all those necessary atomic protons and neutrons. — Andrew Paul, Popular Science, 20 Aug. 2026

In most atoms, the energy needed to flip a neutron in this way would require a gamma-ray laser, which scientists can’t make yet. — Jacek Krywko, Scientific American, 20 Aug. 2026

Most potassium atoms are a stable form known as potassium-39, containing 19 protons and 20 neutrons. — Encyclopedia Britannica, 14 Aug. 2026

Word History

Etymology

probably from neutral

First Known Use

1921, in the meaning defined above

Phrases Containing neutron

• neutron activation analysis
• neutron bomb
• neutron star

Rhymes for neutron

• anton
• argon
• axon
• baronne
• baryon
• baton
• boron
• buisson
• bygone
• capon
• cardon
• chiffon

Kids Definition

neutron

noun

neu·​tron ˈn(y)ü-ˌträn 

: 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 

: 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