ionium
noun
io·ni·um
ī-ˈō-nē-əm 
: a natural radioactive isotope of thorium having a mass number of 230
Examples of ionium in a Sentence
Recent Examples on the Web
Rona set to work isolating a potential new element called ionium.
—
New York Times, 28 Aug. 2019
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
New York Times, 28 Aug. 2019
Cite this Entry
“Ionium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ionium. Accessed 11 Jul. 2025.
Copy CitationMedical Definition
ionium
noun
io·ni·um
ī-ˈō-nē-əm
: a natural radioactive isotope of thorium having a mass number of 230
Love words? Need even more definitions?
Merriam-Webster unabridged
Share