inert

adjective

in·​ert i-ˈnərt 

1

: lacking the power to move

2

: very slow to move or act : sluggish

3

: deficient in active properties

especially : lacking a usual or anticipated chemical or biological action

inert noun

inertly adverb

inertness noun

Synonyms

• dead
• dormant
• fallow
• free
• idle
• inactive
• inoperative
• latent
• off
• unused
• vacant

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

Originally supposed to fly Sierra Space Dream Chaser test flight, but payload switched to an inert mass simulator because of potential Dream Chaser delays beyond October launch date. —Richard Tribou, The Orlando Sentinel, 6 Apr. 2025

But unlike many painting shows at MoMA, those works—mostly paintings, along with a smattering of sculptures and some prints—don’t just hang there, inert. —Alex Greenberger, ARTnews.com, 20 Mar. 2025

By avoiding combustion entirely, these fuel cells allow ammonia’s nitrogen content to remain in its inert form, eliminating a key health risk. —IEEE Spectrum, 10 Mar. 2025

Polymers—very large molecules—are thought to be too big and inert to migrate out of products or into people and therefore pose no health risks. —Arlene Blum, Forbes, 16 Mar. 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