Want of activity or exertion; inertness; quietude.(noun)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "inertion" in a sentence
"Her weak faculties approved of inertion: her brain, her eyes, her ears, her heart slept content; they could not wake to work, so lethargy was their Paradise."
"His former quiet life -- amounting almost to physical inertion -- had given place to a nervous and all-consuming desire to master the rather strenuous art of aviation."
"There had been no flourish of trumpets, no herald of the impending storm, but the pent up forces of revolution in inertion, now fierce for action, discarded restraint."