inertia

[ in-ur-shuh, ih-nur- ]

/ ɪnˈɜr ʃə, ɪˈnɜr- /

noun

inertness, especially with regard to effort, motion, action, and the like; inactivity; sluggishness.

Physics.

the property of matter by which it retains its state of rest or its velocity along a straight line so long as it is not acted upon by an external force.
an analogous property of a force: electric inertia.

Medicine/Medical. lack of activity, especially as applied to a uterus during childbirth when its contractions have decreased or stopped.

Nearby words

Origin of inertia

1705–15; < Latin: lack of skill, slothfulness. See inert, -ia

SYNONYMS FOR inertia

1. torpor, inaction, laziness.

Related formsin·er·tial, adjectivenon·i·ner·tial, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for inertial

Inertial mass is the amount of matter in an object, the measure of the resistance an object has when a force pushes it.
The Equivalence Principle and Testing Einstein With Spaceships and Atoms|Matthew R. Francis|June 4, 2014|DAILY BEAST
"You are, of course, aware of the problems inherent in the development of inertial systems," Marks began.
The Electronic Mind Reader|John Blaine
The delicate accelerometers and inertial guidance components did all the piloting until the second stage kicked us loose.
The Trouble with Telstar|John Berryman
They are the inertial power – rather than the counterfist of reform.
After the Rain|Sam Vaknin

British Dictionary definitions for inertial

inertia

/ (ɪnˈɜːʃə, -ʃɪə) /

noun

the state of being inert; disinclination to move or act

physics

the tendency of a body to preserve its state of rest or uniform motion unless acted upon by an external force
an analogous property of other physical quantities that resist changethermal inertia

Derived Formsinertial, adjective

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for inertial

inertial

adj.

1737, from inertia + -al (1).

inertia

1713, introduced as a term in physics 17c. by German astronomer and physician Johann Kepler (1571-1630), from Latin inertia "unskillfulness, idleness," from iners (genitive inertis) "unskilled, inactive;" see inert. Used in Modern Latin by Newton (1687). Sense of "apathy" first recorded 1822.

Medicine definitions for inertial

inertia

[ ĭ-nûr′shə ]

n.

The tendency of a body to resist acceleration; the tendency of a body at rest to remain at rest or of a body in motion to stay in motion in a straight line unless acted on by an outside force.

Resistance or disinclination to motion, action, or change.

Science definitions for inertial

inertia

[ ĭ-nûr′shə ]

The resistance of a body to changes in its momentum. Because of inertia, a body at rest remains at rest, and a body in motion continues moving in a straight line and at a constant speed, unless a force is applied to it. Mass can be considered a measure of a body's inertia. See more at Newton's laws of motion. See also mass.

Culture definitions for inertial

inertia

[ (i-nur-shuh) ]

In physics, the tendency for objects at rest to remain at rest, and for objects in uniform motion to continue in motion in a straight line, unless acted on by an outside force. (See Newton's laws of motion.)