verb (used without object), i·on·ized, i·on·iz·ing.
  1. to become changed into the form of ions, as by dissolving.
Also especially British, i·on·ise.

Origin of ionize

First recorded in 1895–1900; ion + -ize
Related formsi·on·iz·a·ble, adjectivei·on·i·za·tion, nouni·on·iz·er, nounnon·i·on·ized, adjectivenon·i·on·iz·ing, adjectiveself-i·on·i·za·tion, nounun·i·o·nized, adjectiveun·un·ion·ized, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for ionised

Historical Examples of ionised

British Dictionary definitions for ionised



  1. to change or become changed into ions
Derived Formsionizable or ionisable, adjective
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

Word Origin and History for ionised



1896, from ion + -ize. Related: Ionized; ionizing.

Online Etymology Dictionary, © 2010 Douglas Harper

ionised in Medicine


  1. To dissociate atoms or molecules into electrically charged atoms or radicals.
Related formsion•iz′er n.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

ionised in Science


  1. To give an atom or group of atoms a net electric charge by adding or removing one or more electrons.
  2. To form ions in a substance. Lightning ionizes air, for example.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.