ion

noun
\ ˈī-ən How to pronounce ion (audio) , ˈī-ˌän \

Definition of ion

 (Entry 1 of 3)

1 : an atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one or more electrons
2 : a charged subatomic particle (such as a free electron)

Definition of Ion (Entry 2 of 3)

Ionic

Definition of -ion (Entry 3 of 3)

1a : act or process validation
b : result of an act or process regulation
2 : state or condition hydration

Examples of ion in a Sentence

Recent Examples on the Web: Noun What’s particularly unusual about the AVTR’s drive system, however, is its use of cutting-edge graphene batteries, rather than the lithium-ion technology currently on the market. NBC News, "James Cameron's Avatar comes to life in Mercedes' sleek concept car," 8 Jan. 2020 That siphoning away of the ions allows the catalyst inside the cylinder to work at a faster rate. Robert F. Service, Science | AAAS, "New reactor could halve carbon dioxide emissions from ammonia production," 6 Nov. 2019 In one experiment, a group led by Christopher Monroe of the University of Maryland, College Park, created a time crystal in an engineered system of a chain of ytterbium ions. Frank Wilczek, Scientific American, "The Exquisite Precision of Time Crystals," 16 Oct. 2019 Goodenough, then at Oxford University, discovered that the cathode would have greater potential if it were made with a different material and showed that cobalt oxide, which had layers to hold pockets of lithium ions, could produce a higher voltage. BostonGlobe.com, "Nobel Prize in chemistry honors work on lithium-ion batteries - The Boston Globe," 10 Oct. 2019 In general, they are powered by flows of lithium ions crossing from one material to another. Smithsonian, "Development of the Lithium-Ion Battery Earns Nobel Prize in Chemistry," 10 Oct. 2019 In many forms of epilepsy, however, the movement of ions is not properly controlled. Jenny Wilkerson, chicagotribune.com, "Is CBD a rising star or just a popular fad?," 12 Sep. 2019 Because while other countries have invested public money in the technology, American proponents of carbon ions have been unable to garner federal or private backing. Daniel Oberhaus, WIRED, "A Potent Cancer Therapy, an Instagram Hoax, and More News," 21 Aug. 2019 This was noteworthy because conventional action potentials are usually caused by sodium and potassium ions. Quanta Magazine, "Hidden Computational Power Found in the Arms of Neurons," 14 Jan. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ion.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of ion

Noun

circa 1834, in the meaning defined at sense 1

History and Etymology for ion

Noun

Greek, neuter of iōn, present participle of ienai to go — more at issue entry 1

Noun suffix

French -ion, from Latin -ion-, -io

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Time Traveler for ion

Time Traveler

The first known use of ion was circa 1834

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Statistics for ion

Last Updated

9 Feb 2020

Cite this Entry

“Ion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/-ion. Accessed 18 Feb. 2020.

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More Definitions for ion

ion

noun
How to pronounce -ion (audio)

English Language Learners Definition of ion

 (Entry 1 of 2)

technical : an atom or group of atoms that has a positive or negative electric charge from losing or gaining one or more electrons

English Language Learners Definition of -ion (Entry 2 of 2)

: act or process
: result of an act or process
: state or condition

ion

noun
\ ˈī-ən How to pronounce ion (audio) , ˈī-ˌän \

Kids Definition of ion

: an atom or group of atoms that carries an electric charge

Kids Definition of -ion

1 : act or process construction
2 : result of an act or process regulation eruption
3 : state or condition perfection

ion

noun
\ ˈī-ən How to pronounce ion (audio) , ˈī-ˌän How to pronounce ion (audio) \

Medical Definition of ion

1 : an atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one or more electrons — see anion, cation
2 : a charged subatomic particle (as a free electron)

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More from Merriam-Webster on ion

Rhyming Dictionary: Words that rhyme with ion

Spanish Central: Translation of ion

Nglish: Translation of ion for Spanish Speakers

Britannica English: Translation of ion for Arabic Speakers

Britannica.com: Encyclopedia article about ion

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