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

The most common ions that regulate nerve cell signaling are sodium, potassium, calcium and chloride. Jenny Wilkerson, chicagotribune.com, "Is CBD a rising star or just a popular fad?," 12 Sep. 2019 The entire engine is a single calcium ion, making it around 10 billion times smaller than a car engine. David Grossman, Popular Mechanics, "The Smallest Engine in the World Is Literally an Ion," 22 Aug. 2019 This suite of instruments can measure ions and electrons around the spacecraft at up to 6 times per second. Fox News, "NASA finds evidence of 'interplanetary shock' for first time," 13 Aug. 2019 The particles stay in the gel while releasing a steady stream of silver ions, which are deadly to most infection-causing bacteria. Eva Frederick, Science | AAAS, "This embryo-inspired bandage is 17 times stickier than a Band-Aid," 24 July 2019 The non-hormonal IUD releases copper ions, which are toxic to sperm. Zahra Barnes, SELF, "What to Expect After IUD Removal: Ob/Gyn Experts Explain," 17 July 2019 These metal plates are surrounded by a solution of positive and negative ions, which build up on the plates during charging to deliver electricity. Angela Chen, The Verge, "Supercapacitors power the Note 9 stylus — but are they ready to replace batteries?," 17 Aug. 2018 These lamps are said to generate negative ions, which neutralize toxins, cleansing the air. Rebecca Shinners, Country Living, "The Salt Lamps Everyone Is Obsessed With Are 35% off Today," 17 July 2018 Ola, an Uber competitor in India, is experimenting with e-rickshaws that can exchange lithium ion batteries quickly so there is no downtime for drivers. New York Times, "Inside India’s Messy Electric Vehicle Revolution," 22 Aug. 2019

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

21 Sep 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 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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