Meanings
nounneutronium (uncountable)
- uncountablenatural sciencesA material composed entirely of neutrons.
Synonyms: n, nn (polyneutron), N (nilium), Nt (neutronium, neutrium), nn
- uncountablenatural sciencesA hypothetical gravitationally bound system of a neutron and an antineutron (the onium of a neutron), not predicted to exist under normal circumstances.
Synonyms & antonyms
nounA material composed entirely of neutrons.
Sense 2
Similar
neutron-antineutron systemtrue neutronium
Opposite
antielement 0antielement zeroantineutriumantineutroniumantinilium
Broader
Narrower
dineutronmononeutriummononeutronmononeutroniummononiliumneutronpolyneutriumpolyneutronpolyneutroniumpolyniliumtetraneutrontrineutron
Origin
From neutron + -ium. Coined by scientist Andreas von Antropoff in 1926 (before the discovery of the neutron in 1931; neutrons had been predicted to exist in 1920).
Full word history & related roots →Translations
French neutronium
- neutroniumneutron star material
Italian neutronio
- neutronioneutron star material
Cite this entry
APA
neutronium. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/neutronium
MLA
“neutronium.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/neutronium. Accessed November 4, 2026.
Chicago
WatkinsX Dictionary, s.v. “neutronium,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/neutronium.
Source: neutronium on Wiktionary, CC BY-SA 4.0.