ionium

noun
io·​ni·​um | \ ī-ˈō-nē-əm How to pronounce ionium (audio) \

Definition of ionium

: 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

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ionium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of ionium

1907, in the meaning defined above

History and Etymology for ionium

ion + -ium; so called from its ionizing action

Learn More About ionium

Dictionary Entries Near ionium

Ionism

ionium

ionization

See More Nearby Entries 

Statistics for ionium

Cite this Entry

“Ionium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ionium. Accessed 24 May. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More Definitions for ionium

ionium

noun
io·​ni·​um | \ ī-ˈō-nē-əm How to pronounce ionium (audio) \

Medical Definition of ionium

: a natural radioactive isotope of thorium having a mass number of 230

More from Merriam-Webster on ionium

Britannica.com: Encyclopedia article about ionium

WORD OF THE DAY

Test Your Vocabulary

Name That Food

  • a-light
  • Name these cookies!
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!