inert
Americanadjective
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having no inherent power of action, motion, or resistance (opposed to active).
inert matter.
- Synonyms:
- motionless, lifeless, unmoving, immobile
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Chemistry. having little or no ability to react, as nitrogen that occurs uncombined in the atmosphere.
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Pharmacology. having no pharmacological action, as the excipient of a pill.
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inactive or sluggish by habit or nature.
adjective
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having no inherent ability to move or to resist motion
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inactive, lazy, or sluggish
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having only a limited ability to react chemically; unreactive
Synonym Usage
See inactive.
Other Word Forms
Derived Forms
Etymology
Origin of inert
First recorded in 1640–50; from Latin inert- (stem of iners ) “unskillful,” equivalent to in- in- 3 + -ert-, combining form of art- (stem of ars ) “skill”; see art 1
Explanation
Something that's unable to move or moving without much energy can be described as inert. Wind up in a body cast and you’ll find yourself not only itchy, but totally inert. When motion is restricted or sluggish, or when something or someone appears lifeless, the adjective to use is inert. A dog who's playing dead is inert, as is a really boring movie. Or for those of you paying attention in chemistry class, you may have heard of inert gases — those elements that won't react with other elements or form chemical compounds.
Vocabulary lists containing inert
Anti-Antonyms: Words Without Opposites
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Languor Management: Synonyms for "Lazy"
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And Then There Were None
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
So far, he says, Russian Oreshniks have only been carrying inert warheads and have caused limited damage.
From BBC • May 26, 2026
“The emotive nature of the category, alongside these durable levers that we bring to market, puts us in a category which is relatively much more inert to some of these macro headwinds,” Singh said.
From Barron's • May 19, 2026
If there is a shortfall, there’s about $840 billion in revenue from businesses—entities without claims to clean consciences—raised through customs and corporate income taxes that could be used as morally inert backfill.
From Slate • May 11, 2026
Osborn then falsely reported to the Santa Monica officers that the device was inert, the legal claim alleges.
From Los Angeles Times • May 5, 2026
The rest of us were still sitting around the kitchen table, awkward and inert, pretending to enjoy our second and third cups of coffee when Teddy’s wife marched in.
From "The Secret History" by Donna Tartt
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
