in ‧ er ‧ tia /ɪˈnɜːʃə $ -ɜːr-/ BrE AmE noun [uncountable]
[ Date: 1700-1800 ; Language: Latin ; Origin: iners ; ⇨ ↑ inert ]
1 . when no one wants to do anything to change a situation:
political inertia
2 . technical the force that keeps an object in the same position or keeps it moving until it is moved or stopped by another force
3 . a lack of energy and a feeling that you do not want to do anything SYN apathy
—inertial adjective