a suffix used in the names of complex cations: oxonium.
Origin of -onium
extracted from ammonium
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Medicine definitions for -onium
Containing a positively charged radical:carbonium.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.