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

This blocks defects and halts ion migration, preventing the material from separating over time. — Mrigakshi Dixit, Interesting Engineering, 14 July 2026

While sodium-ion is likely to remain a small fraction of the global battery market, Kikuma said stationary energy storage is one of the fastest growing applications for sodium-ion batteries. — Los Angeles Times, 8 July 2026

Peak makes sodium ion battery cells, and today that type is about 20% more expensive than the more typical lithium ion batteries, Dales said. — Sacbee.com, 8 July 2026

Lithium-ion technology remains dominant today, but emerging alternatives such as sodium-ion batteries could soon further reduce costs and diversify supply chains. — Tom Bitting, Forbes.com, 8 July 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
• herodian
• hawaiian
• ixion
• mauryan
• orion
• procyon
• visayan
• heian
• lion
• mayan

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)