n. 1 Physics a property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force. 2 inertness, sloth. inertia reel a reel device which allows a vehicle seat belt to unwind freely but which locks under force of impact or rapid deceleration. inertia selling the sending of unsolicited goods in the hope of making a sale. inertial adj. inertialess adj.
[ L (as INERT) ]