ion

[ ahy-uhn, ahy-on ]

/ ˈaɪ ən, ˈaɪ ɒn /

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noun Physics, Chemistry.

an electrically charged atom or group of atoms formed by the loss or gain of one or more electrons, as a cation (positive ion ), which is created by electron loss and is attracted to the cathode in electrolysis, or as an anion (negative ion ), which is created by an electron gain and is attracted to the anode. The valence of an ion is equal to the number of electrons lost or gained and is indicated by a plus sign for cations and a minus sign for anions, thus: Na+, Cl−, Ca++, S=.

one of the electrically charged particles formed in a gas by electric discharge or the like.

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Origin of ion

<Greek ión going, neuter present participle of iénai to go; term introduced by Michael Faraday in 1834

Other definitions for ion (2 of 4)

Ion

[ ahy-on ]

/ ˈaɪ ɒn /

noun

Classical Mythology. the eponymous ancestor of the Ionians: a son of Apollo and Creusa who is abandoned by his mother but returns to become an attendant in Apollo's temple at Delphi.

(italics) a drama on this subject (415? b.c.) by Euripides.

Other definitions for ion (3 of 4)

-ion

a suffix, appearing in words of Latin origin, denoting action or condition, used in Latin and in English to form nouns from stems of Latin adjectives (communion; union), verbs (legion; opinion), and especially past participles (allusion; creation; fusion; notion; torsion).

Also -ation, -ition, -tion.

Compare -cion, -xion.

Origin of -ion

<Latin -iōn- (stem of -iō) suffix forming nouns, especially on past participle stems; replacing Middle English -ioun<Anglo-French <Latin -iōn-

Other definitions for ion (4 of 4)

Ion.

abbreviation

Ionic.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use ion in a sentence

I have previously drawn attention to the cargo aboard Flight 370, which included a large consignment of lithium-ion batteries.
The Flight 370 Zombie Theory Rises From the Dead|Clive Irving|June 26, 2014|DAILY BEAST
Last week it made five recommendations directed at the testing and certification of lithium-ion batteries.
NTSB Doesn’t Think the Boeing 787 Dreamliner Is Safe Enough to Fly|Clive Irving|May 28, 2014|DAILY BEAST
Lithium-ion batteries will further increase underwater performance.
Tomorrow’s Stealthy Subs Could Sink America’s Navy|Bill Sweetman|May 12, 2014|DAILY BEAST
How can this saga of the lithium-ion batteries be tied to the fate of Flight 370?
Passenger Flights Must Stop Carrying Lithium-Ion Batteries as Cargo|Clive Irving|May 5, 2014|DAILY BEAST

A month after that announcement, unaccustomed daylight was forced upon the lithium-ion battery industry.
Passenger Flights Must Stop Carrying Lithium-Ion Batteries as Cargo|Clive Irving|May 5, 2014|DAILY BEAST
A merry, happy time the children had, and on reaching Ion the little ones were ready for their supper and bed.
Elsie's Vacation and After Events|Martha Finley
At Ion Grandma Elsie lay quietly sleeping, her three daughters watching over her with tenderest care and solicitude.
Elsie's Vacation and After Events|Martha Finley
In other words, five hydrogen ions passed to the right, while one chloride ion passed to the left.
The Elements of Qualitative Chemical Analysis, vol. 1, parts 1 and 2.|Julius Stieglitz
That is, different concentrations of hydrogen-ion or of hydroxide-ion are required to change their colors.
The Elements of Qualitative Chemical Analysis, vol. 1, parts 1 and 2.|Julius Stieglitz
The second table gives, similarly, the concentrations of hydroxide-ion required to produce the changes of tint indicated.
The Elements of Qualitative Chemical Analysis, vol. 1, parts 1 and 2.|Julius Stieglitz

British Dictionary definitions for ion (1 of 2)

ion

/ (ˈaɪən, -ɒn) /

noun

an electrically charged atom or group of atoms formed by the loss or gain of one or more electronsSee also cation, anion

Word Origin for ion

C19: from Greek, literally: going, from ienai to go

British Dictionary definitions for ion (2 of 2)

-ion

suffix forming nouns

indicating an action, process, or statecreation; objection Compare -ation, -tion

Word Origin for -ion

from Latin -iōn-, -io

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for ion

ion

[ ī′ən, ī′ŏn′ ]

An atom or a group of atoms that has an electric charge. Positive ions, or cations, are formed by the loss of electrons; negative ions, or anions, are formed by the gain of electrons.

Cultural definitions for ion

ion

[ (eye-uhn, eye-on) ]

An atom that has either lost or gained one or more electrons, so that it has an electrical charge. Ions can be either positively or negatively charged.