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

• 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

Save some dough by filling the bottom third of the pot with inert materials such as blocks of polystyrene foam from product packaging or packing peanuts (secured in plastic bags). —Luke Miller, Better Homes & Gardens, 17 June 2025

The defense argued that Gutierrez Reed could not have anticipated that a box of inert dummy rounds had been contaminated with a handful of similar-looking live bullets. —Gene Maddaus, Variety, 24 May 2025

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, 18 June 2025

It can’t be created by repairing the existing organization, like fixing an inert machine. —Steve Denning, Forbes.com, 15 June 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