Synonyms of inert

inert

adjective

i-ˈnərt 

1

as in dormant

not being in a state of use, activity, or employment

the inert, abandoned factories that are scattered all over that dying city

Synonyms & Similar Words

• dormant
• off
• vacant
• idle
• unused
• inactive
• dead
• inoperative
• latent
• at rest
• out of commission
• free
• fallow
• useless
• on the shelf
• suspended
• lifeless
• unusable
• unoccupied
• quiescent
• asleep
• comatose
• arrested
• moribund
• interrupted
• slow
• unworkable
• inoperable
• sleepy
• abeyant
• dull

Antonyms & Near Antonyms

• active
• operating
• functioning
• operative
• alive
• on
• busy
• functional
• employed
• working
• operational
• living
• workable
• going
• operable
• industrious
• practical
• running
• useful
• energetic
• vigorous
• viable
• feasible
• usable
• assiduous
• sedulous
• useable

2

as in sleepy

slow to move or act

a sleepy, inert reptile that is no threat to people when left alone

Synonyms & Similar Words

• sleepy
• dull
• inactive
• quiescent
• motionless
• torpid
• lethargic
• sluggish
• lazy
• resting
• static
• inanimate
• listless
• dormant
• apathetic
• indolent
• shiftless
• slothful
• sedentary
• languorous
• still
• asleep
• drugged
• ambitionless
• dead
• slack
• dopey
• comatose
• catatonic
• drowsy
• sluggardly
• lazyish
• dopy
• somnambulant
• sluggard

Antonyms & Near Antonyms

• active
• engaged
• occupied
• busy
• dynamic
• working
• kinetic
• energetic
• vigorous
• vital
• lively
• spirited
• animated
• vivacious
• bouncing
• sprightly
• industrious
• diligent
• perky
• springy
• assiduous
• hardworking
• peppy
• zippy
• sedulous

Synonym Chooser

How is the word inert different from other adjectives like it?

Some common synonyms of inert are idle, inactive, passive, and supine. While all these words mean "not engaged in work or activity," 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

When would idle be a good substitute for inert?

The words idle and inert can be used in similar contexts, but idle applies to persons that are not busy or occupied or to their powers or their implements.

workers were idle in the fields

In what contexts can inactive take the place of inert?

While in some cases nearly identical to inert, inactive applies to anyone or anything not in action or in operation or at work.

on inactive status as an astronaut

inactive accounts

When can passive be used instead of inert?

The words passive and inert are synonyms, but do differ in nuance. Specifically, 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

When could supine be used to replace inert?

While the synonyms supine and inert are close in meaning, supine applies only to persons and commonly implies abjectness or indolence.

a supine willingness to play the fool

Example Sentences

Recent Examples of inert

An active comparator might also be used rather than an inert placebo because of ethics. —Brenda Goodman, CNN Money, 5 June 2025

The Trump administration has also said new Covid vaccines must undergo clinical trials with an inert placebo — meaning some participants would receive the new vaccine while others would receive an inactive substance like saline, to compare results. —Aria Bendix, NBC news, 1 June 2025

Pure gold is inert in Earth’s mantle and tends to stay there. —David Bressan, Forbes.com, 23 May 2025

Mercury, Mars and the moon appear essentially inert. —Elise Cutts, Scientific American, 13 May 2025