onium

adjective
oni·​um | \ ˈō-nē-əm How to pronounce onium (audio) \

Definition of onium

 (Entry 1 of 2)

: being or characterized by a usually complex cation

Definition of -onium (Entry 2 of 2)

: an ion having a positive charge hydronium — compare -ium sense 1b

First Known Use of onium

Adjective

1905, in the meaning defined above

History and Etymology for onium

Adjective

-onium

Noun suffix

New Latin, from ammonium

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Time Traveler for onium

Time Traveler

The first known use of onium was in 1905

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Cite this Entry

“Onium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/onium. Accessed 21 Jan. 2021.

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More Definitions for onium

onium

adjective
oni·​um | \ ˈō-nē-əm How to pronounce onium (audio) \

Medical Definition of onium

: being or characterized by a usually complex cation onium salts

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