inertia

noun in·er·tia \ i-ˈnər-shə , -shē-ə \

|Updated on: 10 Jun 2018

Definition of inertia

1 a : a property of matter by which it remains at rest or in uniform motion in the same straight line unless acted upon by some external force

b : an analogous property of other physical quantities (such as electricity)

2 : indisposition to motion, exertion, or change : inertness

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inertial

play \i-ˈnər-shəl, -shē-əl\ adjective

—

inertially

play \i-ˈnər-sh(ə-)lē\ adverb

See inertia defined for English-language learners

See inertia defined for kids

Examples of inertia in a Sentence

He blames governmental inertia for the holdup.
After 10 years in an unsatisfying job she overcame her inertia and went back to school.

Recent Examples of inertia from the Web

When politics is so contested, and the two parties that represent reactionary and progressive attitudes are more or less evenly matched, inertia becomes normal.

— jason pontin, WIRED, "Four Rules for Learning How to Talk To Each Other Again," 25 May 2018
Right now, the habits and patterns of decision-making shaped by low VRE penetration still have inertia, exacerbated by the lingering doubt Trump has imposed on power markets.

— david roberts, Vox, "Wind and solar are coming. Grid managers need to get ready.," 18 May 2018
Europe’s foreign-policy elites, taking their cues from Germany’s placid Angela Merkel, acted as though their high-toned inertia would make the Trump administration’s concerns just . . .

— daniel henninger, WSJ, "It’s Trump’s Iran Deal Now," 9 May 2018
There’s a lot of institutional inertia around that.

— german lopez, Vox, "Why some US cities are opening safe spaces for injecting heroin," 3 May 2018
Lelio could have perhaps done a better job of acknowledging the inexorable power of inertia.

— david sims, The Atlantic, "Disobedience Is a Drab Story of Forbidden Love," 27 Apr. 2018
The long-term neglect, inertia and disarray concerning information security at Interior and other parts of the federal bureaucracy dates back to the Obama administration and beyond.

— george russell, Fox News, "Cybersecurity fiasco: Interior Department computers trying to talk to Russia, inspectors say," 5 Apr. 2018
Culture is more effective than law at enforcing good behavior—and abuse nearly always trades on a culture of ignorance, credulity, and inertia.

— james scott, Fortune, "Commentary: Sweden Actually Protects its Residents’ Data. America Should Take Note.," 13 Apr. 2018
Next to him, a group of young women are debating where to go next, struggling between ambition and inertia.

— samantha melamed, Philly.com, "I went to visit the ruins of the Piazza, and found Urban Village Brewing Co.," 11 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'inertia.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Did You Know?

Inertia is the inherent property of a body that makes it oppose any force that would cause a change in its motion. A body at rest and a body in motion both oppose forces that might cause acceleration. The inertia of a body can be measured by its mass, which governs its resistance to the action of a force, or by its moment of inertia about a specified axis, which measures its resistance to the action of a torque about the same axiss.

Origin and Etymology of inertia

New Latin, from Latin, lack of skill, from inert-, iners

NEW! Time Traveler

First Known Use: 1713

in the meaning defined at sense 1a

See Words from the same year

inertia Synonyms

Other Physics Terms

amplitude, centrifugal, centripetal, convection, gradient, hysteresis, kinetic, lase, quantum

INERTIA Defined for English Language Learners

inertia

noun

Definition of inertia for English Language Learners

: lack of movement or activity especially when movement or activity is wanted or needed
: a feeling of not having the energy or desire that is needed to move, change, etc.
physics : a property of matter by which something that is not moving remains still and something that is moving goes at the same speed and in the same direction until another thing or force affects it