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

The result depends on the assumption that nuclear reaction rates and neutron decay follow the same scaling as the expansion rate. — Rupendra Brahambhatt, Interesting Engineering, 8 Nov. 2026

Lightbulb was also accompanied by a kilonova, a bright surge of radiation involving oodles of neutrons—the very kind that could kick-start the r-process and forge all those heavy elements. — Robin George Andrews, Scientific American, 20 Oct. 2026

Back in orbit, NASA's MEGANE instrument will measure Phobos' elemental composition through gamma-ray and neutron spectroscopy that can scan tens of centimeters beneath the moon's surface for signs of volatile elements. — Josh Dinner, Space.com, 18 Oct. 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