inertia

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

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

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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

The turbochargers' compressor wheels are made of a titanium-aluminum alloy that the carmaker says has a low inertia, and the length of the pipework has been optimized to shorten the gas' journey as much as possible.

— jonathan m. gitlin, Ars Technica, "Road tripping in a Ferrari 488 GTB: Worth the wait," 12 Aug. 2017
Each new administration has little more than a year to achieve its biggest goals before political campaigning and Washington inertia overtake policy making.

— justin sink, Bloomberg.com, "Trump Hits Reset Button by Ousting Priebus After Rough Week," 29 July 2017
Hogan is already getting heat from potential gubernatorial rivals over his inertia, including from Baltimore County Executive Kevin Kamenetz and Baltimore County resident Ben Jealous.

— barry rascovar, baltimoresun.com, "Health care puts Hogan in a precarious position," 18 July 2017
That leaves foreign policy, an arena also marked by inertia.

— The Economist, "If Donald Trump won a second termSuppose the Trump show runs and runs," 13 July 2017
Legislative inertia means inflation expectations are starting to dissipate.

— erin arvedlund, Philly.com, "What's the return on your Pa. or N.J. college investment?," 10 July 2017
This came from Catapult's inertia movement analysis, which quantifies the degree of a player's movement in three-dimensional space from forward to back, left to right and even up and down.

— rainer sabin, AL.com, "Inside the technology giving Alabama a competitive edge," 2 July 2017
So much energy was in that air mass, the setting sun had little effect; thermal inertia maintained extreme instability into the late evening.

— jeff halverson, Washington Post, "Five years ago the derecho ravaged Washington. It will happen again. Will we be ready?," 29 June 2017
Nevertheless, the ultimate decision rested with Ru, who has seen both Sasha and Peppermint excel throughout the entire competition, with Sasha having an edge of consistency and Pepper riding a wave of late-in-the-game inertia.

— marc snetiker, PEOPLE.com, "RuPaul's Drag Race," 24 June 2017

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

See Words from the same year

inertia Synonyms

Synonyms

idleness, indolence, laziness, shiftlessness, sloth

Antonyms

drive, industriousness, industry

Related Words

apathy, languor, lassitude, lethargy, listlessness, sluggishness, supineness; dallying, goldbricking, loafing, lolling, lounging

Near Antonyms

ambition, enterprise, go, hustle, initiative; assiduity, assiduousness, diligence, perseverance; animation, briskness, energy, exuberance, jazziness, liveliness, lustiness, pep, peppiness, robustness, sprightliness, vibrancy, vigor, vim, vitality, vivacity

Other Physics Terms

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

INERTIA Defined for English Language Learners

inertia

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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

INERTIA Defined for Kids

inertia

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noun in·er·tia \ i-ˈnər-shə \

Definition of inertia for Students

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

2 :a tendency not to move or change

He stayed at the job mostly because of his inertia.

Medical Dictionary

inertia

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noun in·er·tia \ in-ˈər-shə, -shē-ə \

medical 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 (as electricity)

2 :lack of activity or movement —used especially of the uterus in labor when its contractions are weak or irregular

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Origin and Etymology of inertia

inertia Synonyms

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INERTIA Defined for English Language Learners

inertia

Definition of inertia for English Language Learners

INERTIA Defined for Kids

inertia

Definition of inertia for Students

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inertia

medical Definition of inertia

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