from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The positively charged ion of hydrogen, H+, formed by removal of the electron from atomic hydrogen and found in the form of hydronium ion in all aqueous solutions of acids.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun chemistry Used other than as an idiom: see hydrogen,‎ ion. ; H- or H+
  • noun chemistry a proton combined with one or more water molecules; usually written H3O+ and called the hydronium ion though is best considered as H9O4+ but is often written H+(aq) for simplicity
  • noun chemistry a bare hydrogen nucleus; a proton , deuteron or triton

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a positively charged atom of hydrogen; that is to say, a normal hydrogen atomic nucleus


Sorry, no etymologies found.


Help support Wordnik (and make this page ad-free) by adopting the word hydrogen ion.


    Sorry, no example sentences found.


Log in or sign up to get involved in the conversation. It's quick and easy.