- inactiveness, inactivity, inertia - a disposition to remain inactive or inert; "he had to overcome his inertia and get back to work"
--1 is a kind of trait
--1 has particulars:languor, lethargy, sluggishness, phlegm; restfulness; passivity, passiveness; indolence, laziness - inertia - (physics) the tendency of a body to maintain is state of rest or uniform motion unless acted upon by an external force
--2 is a kind of mechanical phenomenon
--2 has particulars: moment of inertia