inertia

Etymology

From Latin inertia (“lack of art or skill, inactivity, indolence”), from iners (“unskilled, inactive”), from in- (“without, not”) + ars (“skill, art”). The modern physics sense was first used in New Latin by Johannes Kepler.

noun

1. (physics, uncountable or countable) The property of a body that resists any change to its uniform motion; equivalent to its mass.
2. (figurative) In a person, unwillingness to take action.
   Not all the surviving veteran chiefs would actually fight. Some remained nominally in the resistance but in practice delayed at their bases, pretexting a lack of ammunition for their uncertain inertia. 12 August 1970 [15 January 1969], John Womack, Jr., Zapata and the Mexican Revolution, New York: Knopf Doubleday Publishing Group, →LCCN, →OCLC, →OL, page 261
   City had been woeful, their anger at their own inertia summed up when Samir Nasri received a booking for dissent, and they did not have a shot on target until the 66th minute. 9 March 2014, Jacob Steinberg, “Wigan shock Manchester City in FA Cup again to reach semi-finals”, in The Guardian
3. (medicine) Lack of activity; sluggishness; said especially of the uterus, when, in labour, its contractions have nearly or wholly ceased.