"inertia" in the noun sense
1. inactiveness, inactivity, inertia
a disposition to remain inactive or inert
"he had to overcome his inertia and get back to work"
2. inertia
physics) the tendency of a body to maintain its state of rest or uniform motion unless acted upon by an external force
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License