inert

adjective

in·​ert i-ˈnərt How to pronounce inert (audio)
Synonyms of inert
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

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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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Like the Chinese test facility, the KRONOS design uses inert helium rather than liquid water to cool the reactor core. — Aman Tripathi, Interesting Engineering, 31 July 2026 This summer alone, TSA has found two live smoke grenades, an inert grenade, a pipe bomb look-alike and a samurai sword hidden in a guitar case. — CBS News, 30 July 2026 The Baldwin County Sheriff's Office responded, and authorities considered whether a bomb squad would be needed before determining the cannonballs were inert. — Anthony Thompson, USA Today, 28 July 2026 To varying degrees, the commission became inert and was unable to yield money or power to back this campaign. — Literary Hub, 27 July 2026 See All Example Sentences for inert

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

Time Traveler
The first known use of inert was in 1647

Phrases Containing inert

Rhymes for inert

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Browse Nearby Words

in error
inert
inertance
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Cite this Entry

“Inert.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/inert. Accessed 6 Aug. 2026.

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Kids Definition

inert

adjective
in·​ert in-ˈərt How to pronounce inert (audio)
: 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 How to pronounce inert (audio)
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

More from Merriam-Webster on inert

Nglish: Translation of inert for Spanish Speakers

Last Updated: - Updated example sentences
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