inert

adjective

in·​ert i-ˈnərt 

1

: lacking the power to move

an inert and lifeless body

2

: very slow to move or act : sluggish

an inert administration

3

: deficient in active properties

especially : lacking a usual or anticipated chemical or biological action

inert noun

inertly adverb

inertness noun

Synonyms of inert

• dormant
• off
• vacant
• idle
• unused

Choose the Right Synonym for inert

inactive, idle, inert, passive, supine mean not engaged in work or activity.

inactive applies to anyone or anything not in action or in operation or at work.

on inactive status as an astronaut

inactive accounts

idle applies to persons that are not busy or occupied or to their powers or their implements.

workers were idle in the fields

inert as applied to things implies powerlessness to move or to affect other things; as applied to persons it suggests an inherent or habitual indisposition to activity.

inert ingredients in drugs

an inert citizenry

passive implies immobility or lack of normally expected response to an external force or influence and often suggests deliberate submissiveness or self-control.

passive resistance

supine applies only to persons and commonly implies abjectness or indolence.

a supine willingness to play the fool

Examples of inert in a Sentence

an inert and lifeless body

How does he propose to stimulate the inert economy and create jobs?

Recent Examples on the Web

Supplied by Mercer Rosenthal GmbH, a German pulp mill, the lignin was thermally treated under inert conditions. —Georgina Jedikovska, Interesting Engineering, 3 Nov. 2025

Such is the lot of young Miguel (Julio Pena Hernandez), who had recently suffered wounds in sea battle that rendered his left arm permanently inert. —Dennis Harvey, Variety, 31 Oct. 2025

In Robert Towne’s visually striking but dramatically inert adaptation of John Fante’s novel, Farrell plays an aspiring writer who moves to Los Angeles and falls in love with a beautiful Mexican waitress, played by Salma Hayek. —Bilge Ebiri, Vulture, 30 Oct. 2025

Released in 1938 and technically known as Polytetrafluoroethylene (PTFE), the chemically inert, synthetic polymer is most famous for providing impressively nonstick coatings on cookware and other surfaces. —Andrew Paul, Popular Science, 22 Oct. 2025

Word History

Etymology

Latin inert-, iners unskilled, idle, from in- + art-, ars skill — more at arm

First Known Use

1647, in the meaning defined at sense 1

Phrases Containing inert

• inert gas

Rhymes for inert

• alert
• assert
• avert
• dessert
• divert
• evert
• exert
• insert
• invert
• nightshirt
• overt
• revert

Kids Definition

inert

adjective

in·​ert in-ˈərt 

: unable or slow to move, act, or react

inert ingredients in cough medicine

inert gas

inertly adverb

inertness noun

Medical Definition

inert

adjective

in·​ert in-ˈərt 

1

: lacking the power to move

2

: deficient in active properties

especially : lacking a usual or anticipated chemical or biological action

an inert drug

inertness noun