inertia

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

Updated on: 16 Apr 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

—

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

The kids of Stoneman Douglas Elementary school did not bust inertia in Congress over changing federal gun laws.

— stephen collinson, CNN, "From teens to teachers, activism stirs the electorate," 3 Apr. 2018
My mother suffered from severe recurring depression for 30 years, episodes that floored her to the point of near-catatonic inertia.

— anthea rowan, idahostatesman, "After a stroke, Mum’s decades of severe depression vanished | Idaho Statesman," 15 Mar. 2018
The average financial institution, banking on customer inertia, has been much slower to respond.

— kathleen pender, San Francisco Chronicle, "It’s time to shop for a better savings rate," 3 Feb. 2018
If he is forced to scale back his plans, economists warn that France risks slipping back into inertia, hamstringing its growth prospects compared with other European countries.

— william horobin, WSJ, "French Labor Strikes Pose a Test to Macron’s Overhauls," 22 Mar. 2018
The #metoo disclosures were a global keening, which rent a hole in the collective inertia.

— monitor editors, The Christian Science Monitor, "Tariffs miss the mark, Protectionism favors powerful nations, Children should not be targeted for taking a stand, Five Star Movement’s win in Italy continues a populist trend, Better avenues needed for reporting sexual harassment," 17 Mar. 2018
My mother suffered from severe recurring depression for 30 years, episodes that floored her to the point of near-catatonic inertia.

— anthea rowan, idahostatesman, "After a stroke, Mum’s decades of severe depression vanished | Idaho Statesman," 15 Mar. 2018
Much of the inertia in fixing the problem is the result of the comparative lack of harm posed to the memcached servers.

— dan goodin, Ars Technica, "It just got much easier to wage record-breaking DDoSes," 7 Mar. 2018
Institutional inertia is an issue across the U.S., observes Mark Graber, president and co-founder of the Society to Improve Diagnosis in Medicine.

— dina fine maron, Scientific American, "Sophisticated Digital Aids Could Help Determine What Ails You," 1 Aug. 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

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