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# muonium
- URL: https://keithhayden.net/muonium/
- Published: 2026-08-21T16:11:00.000Z
- Updated: 2026-08-22T22:52:01.000Z
- Description: A physics / particle physic term
- Author: Keith Hayden
- Tags: #hfd-word

21 AUG 2026 

0/5 word facts discovered 

## muonium

/mjuːˈoʊniəm/

noun

A short-lived quasi-atom consisting of an electron and a positive muon.

muonium 21·08·26 

QUASI atom-like · not an element 

01 Keith’s definition 

Probably some type of synthetic element in the 110s range on the periodic table? Never heard of it.

02 Official meaning 

A short-lived quasi-atom consisting of an electron and a positive muon.

03 In use 

> “You finished logging that muonium observation yet?” Of extreme sensitivity in the sterile lab, my partner—a boorish, plodding woman middle-aged and mid looks—asked again. This second time sealed my descent to darkness.

04 Hear it 

FIELD RECORDING · KEITH HAYDEN 

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### Useless facts

- **11 points.** MUONIUM is a legal seven-letter Scrabble word; its plural is *muoniums*.
- **The word got there first.** Its first known use dates to 1957; muonium was experimentally observed in 1960.
- **No protons allowed.** A muonium atom contains neither a proton nor a neutron.
- **Dictionary neighbors.** *Muong*, a people and language related to Vietnamese, lives on one side; *Mur*, a European river, lives on the other.
- **Element zero.** Muonium behaves like an ultralight, extremely short-lived isotope of hydrogen.
- **A misleading name.** Under the modern naming pattern, a muon–antimuon pair gets the wonderfully corrective name *true muonium*.

HAYDEN’S FIELD DICTIONARY [ ← Return to the Word Archive ](https://keithhayden.net/haydens-field-dictionary-archive/) 

WORD COMPLETE **muonium** noun 5 FACTS RECOVERED FIELD ARCHAEOLOGIST **YOU**