ion

1 of 3

noun

ˈī-ən  ˈī-ˌän 

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)

Ion

2 of 3

abbreviation

Ionic

-ion

3 of 3

noun suffix

1

a

: 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 model is based on how lithium ions propagate through a battery’s electrodes, similar to how caffeine molecules dissolve from coffee grounds. —ArsTechnica, 28 Apr. 2026

In 2021 the company unveiled a first-generation sodium-ion cell with an energy density of 160 Wh/kg. —Omar Kardoudi april 28, New Atlas, 28 Apr. 2026

Previous attempts at extracting uranium ions have relied on a passive system in which adsorbents remain stationary and wait for uranium ions to pass through them for trapping. —Ameya Paleja, Interesting Engineering, 27 Apr. 2026

This X-ray glow is radiated when the heavy ions of the solar wind, like carbon and oxygen, grab an electron from neutral atoms in either our outer atmosphere or the heliosphere. —Robert Lea, Space.com, 24 Apr. 2026

Word History

Etymology

Noun

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

Noun suffix

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

First Known Use

Noun

circa 1834, in the meaning defined at sense 1

Phrases Containing ion

• hydrogen ion
• ion channel
• ion engine
• ion exchange
• ion exchange resin
• lithium-ion battery

Rhymes for ion

• amphitryon
• dandelion
• hawaiian
• ixion
• orion
• procyon
• visayan
• heian
• lion
• mayan
• scion

Kids Definition

ion

1 of 2 noun

ˈī-ən 

ˈī-ˌän

: 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

-ion

2 of 2 noun suffix

1

a

: act or process

validation

b

: result of an act or process

regulation

2

: state or condition

hydration

Etymology

Noun suffix

derived from Latin -ion (suffix) "act or process"

Medical Definition

ion

noun

ˈī-ən  ˈī-ˌän 

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)