a suffix, appearing in words of Latin origin, denoting action or condition, used in Latin and in English to form nouns from stems of Latin adjectives (communion; union), verbs (legion; opinion), and especially past participles (allusion; creation; fusion; notion; torsion).
ionRead more in this article about some frequently asked questions and fun facts related to our definitions.
If you see an odd glow in the sky tonight, here’s what it’s called and its causeYou’ve heard of the northern lights? The next few days you may be able to see lights even if you aren’t that far north. The sun erupted on Sunday, spewing plasma, “a highly ionized gas containing an approximately equal number of positive ions and electrons” right in our direction. There’s no reason to freak out; solar storms are relatively common, and the most significant impact they have on …
Origin of -ion
< Latin -iōn- (stem of -iō) suffix forming nouns, especially on past participle stems; replacing Middle English -ioun < Anglo-French < Latin -iōn-
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
suffix forming nouns
Word Origin for -ion
from Latin -iōn-, -io
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
suffix forming nouns of state, condition, or action from verbs, from Latin -ionem (nominative -io), sometimes via French -ion.
Online Etymology Dictionary, © 2010 Douglas Harper