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 design improves how ions move and how the battery reacts chemically. —Mrigakshi Dixit, Interesting Engineering, 24 Nov. 2025

This lowers the amount of oxygen ions, which are required to make the hydrogen particles that repair the plasmasphere. —Andrew Paul, Popular Science, 20 Nov. 2025

There are emission lines, which is what happens when atoms, molecules, or ions have electrons in an excited state. —Big Think, 19 Nov. 2025

Click here for more Space.com videos... Virtual Telescope Project founder Gianluca Masi captured a stunning image of comet 3I/ATLAS on Nov. 11, which revealed the interstellar invader's glowing central coma and lengthening smoke-like ion tail being carried away by the solar wind. —Anthony Wood, Space.com, 16 Nov. 2025

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)