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 way, the zwitterionic polymer could bind water tightly enough to prevent it from splitting at higher voltages while still releasing lithium ions when needed. —ArsTechnica, 14 Apr. 2025

Interestingly, the team observed an odd ion enhancement pattern, where the ionization or excitation of an element or molecule is increased by the presence of another. —Victoria Corless, Space.com, 11 Apr. 2025

Both rockets released their payloads—think ion guages, magnetometers, and vapor chasers; the latter released colorful puffs of gas—during an auroral substorm. —Michael D'estries, Travel + Leisure, 7 Apr. 2025

Now the new study, led by UNM professor Brent Wagner, MD, has found a connection between gadolinium and oxalic acid, a molecule found in foods which binds with metal ions, leading to medical issues such as kidney stones. —John W. Dean, MSNBC Newsweek, 7 Apr. 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)