1.Physics The tendency of a body to resist acceleration; the tendency of a body at rest to remain at rest or of a body in straight line motion to stay in motion in a straight line unless acted on by an outside force. 2. Resistance or disinclination to motion, action, or change: the inertia of an entrenched bureaucracy.
ETYMOLOGY:
Latin, idleness, from iners, inert-, inert. See inert.