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.
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
Philosophy without a biography turns inhuman; biography without a philosophy becomes inert.
From The Wall Street Journal • Mar. 6, 2026
But for at least a little while, within the confines of San Francisco’s Moscone Center, there was a glimmer of a life in a contest that has seemed largely inert.
From Los Angeles Times • Feb. 22, 2026
At first glance, the moon appears lifeless and inert.
From Science Daily • Jan. 5, 2026
As it sank he became less and less frenzied; and just as it dipped he slid from the hands that held him, an inert mass, on the floor.
From "Dracula" by Bram Stoker
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.
