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-onium

American  
Chemistry.

  1. a suffix used in the names of complex cations.

    oxonium.

Etymology

Origin of -onium

Extracted from ammonium

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.