ion

noun
\ ˈī-ən , 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

Some polymers can conduct ions, but that usually only works at extremely high temperatures. Angela Chen, The Verge, "The best solution for making batteries safer might be the most boring one," 13 Aug. 2018 When a battery is fully charged, the anode has sucked up lithium ions like a sponge. Christopher Mims, WSJ, "The Battery Boost We’ve Been Waiting for Is Only a Few Years Out," 18 Mar. 2018 The steady improvement in lithium-ion batteries’ energy and power-density over cost will render the latest plug-in hybrids comically superfluous in a matter of years. Dan Neil, WSJ, "Think Electric Vehicles Are Great Now? Just Wait...," 26 Dec. 2018 The main lithium-ion battery sits in a cast-aluminum housing, with a second 12-volt li-ion battery for lights, the dash, and horn. Alexander George, Popular Mechanics, "The Harley-Davidson LiveWire Electric Motorcycle Goes Public," 6 Nov. 2018 The silver ions found in this wash have some serious antiseptic powers. Megan Mcintyre, Glamour, "This Face Wash Is the Only Thing That Helped My Acne," 29 Aug. 2018 The lithium ion battery is built into the platform, takes about four to five hours to fully charge, and has a range of over 15 miles. Andrew J. Hawkins, The Verge, "Unagi is the $1,190 electric scooter you won’t want to share with anyone," 17 Nov. 2018 In March, John and Sandra Hedlund, both 74, invested $80,000 in a hybrid system for their home in Virginia’s Tidewater region, with 84 rooftop solar panels linked to a LG lithium ion battery. Amy Gamerman, WSJ, "The Homes Where Families Go Off the Grid," 27 Sep. 2018 One of the problems could be that our understanding of the movements of the lithium compounds used in batteries is rather poorly understood, especially because looking at the ions at nanoscale hasn't been possible until recently. John Wenz, Popular Mechanics, "Scientists May Have Found What Makes Batteries Degrade Over Time," 17 Sep. 2018

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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Dictionary Entries near ion

iolite

IOM

Io moth

ion

Ion

-ion

Iona

Statistics for ion

Last Updated

9 Feb 2019

Look-up Popularity

Time Traveler for ion

The first known use of ion was circa 1834

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More Definitions for ion

ion

noun

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 , 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 , ˈī-ˌän \

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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