: a process by which an excited atom becomes ionized and goes to a lower energy state by emitting one of two or more excited electrons that together possess energy exceeding the atom's ionization energy
especially : such a process yielding an electron having an energy equivalent to that of a photon of optical wavelength compare auger effect
" +

Word History


aut- + ionization

First Known Use

1931, in the meaning defined above

Time Traveler
The first known use of autoionization was in 1931

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Dictionary Entries Near autoionization

Cite this Entry

“Autoionization.” Dictionary, Merriam-Webster, Accessed 28 May. 2024.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!