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 works by ionizing atoms belonging to a gaseous propellant, such as xenon or krypton, and then accelerating those ions out through a nozzle to provide thrust. —Keith Cooper, Space.com, 27 Mar. 2026

However, the real breakthrough came with their hybrid lithium-ion supercapacitors. —Mrigakshi Dixit, Interesting Engineering, 25 Mar. 2026

When the temperature exceeds 26 degrees Celsius (79 degrees Fahrenheit), the TRPM8 ion permeation channel—the hole in the doughnut—is closed. —Jacek Krywko, Scientific American, 25 Mar. 2026

The former material is great for absorbing lithium ions and improving energy storage abilities, white the latter houses large amounts of charge thanks to its spacious internal surface area. —Andrew Paul, Popular Science, 25 Mar. 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)