[ ahy-uh-nahyz ]

verb (used with object),i·on·ized, i·on·iz·ing.
  1. to separate or change into ions.

  2. to produce ions in.

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

Origin of ionize

First recorded in 1895–1900; ion + -ize
  • Also especially British, i·on·ise .

Other words from ionize

  • i·on·iz·a·ble, adjective
  • i·on·i·za·tion, noun
  • i·on·iz·er, noun
  • non·i·on·ized, adjective
  • non·i·on·iz·ing, adjective
  • self-i·on·i·za·tion, noun
  • un·i·o·nized, adjective
  • un·un·ion·ized, adjective

Words Nearby ionize Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use ionize in a sentence

  • Second, the upper atmosphere of Eisberg was pretty much pure hydrogen, which is somewhat easier to ionize than oxygen or nitrogen.

    Unwise Child | Gordon Randall Garrett
  • Inorganic materials, when dissolved in water, usually ionize very readily.

    The Chemistry of Plant Life | Roscoe Wilfred Thatcher
  • Certain ultra-violet rays also ionize the air and cause the formation of ozone.

    Artificial Light | M. Luckiesh
  • He's developed a system, which, thanks to the power we can get in that atostor, will sextuply ionize oxygen gas.

    The Ultimate Weapon | John Wood Campbell
  • Organic compounds, on the other hand, ionize only very slowly, if at all.

    The Chemistry of Plant Life | Roscoe Wilfred Thatcher

British Dictionary definitions for ionize



/ (ˈaɪəˌnaɪz) /

  1. to change or become changed into ions

Derived forms of ionize

  • ionizable 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

Scientific definitions for ionize


[ īə-nīz′ ]

  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.