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
Related Words
See inactive.
Other Word 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.
The state investigator also requested the X-ray tests that deputies had used to wrongly determine that the two grenades were inert, according to the complaint.
From Los Angeles Times • Apr. 1, 2026
"We write information into stable, inert materials that can withstand the passage of time and remain fully accessible to future generations."
From Science Daily • Mar. 29, 2026
Buffett acknowledged that an inert asset might thrive at times as an object of speculation or when it’s driven by fear about things like war or the value of the dollar.
From The Wall Street Journal • Feb. 27, 2026
Lutnick’s testimony this past week, like Bondi’s, is thus operating as a still life in what happens when the law becomes inert.
From Slate • Feb. 12, 2026
Together Armstrong and Lombard had carried the inert body of Anthony Marston to his bedroom and had laid him there covered over with a sheet.
From "And Then There Were None" by Agatha Christie
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.
