- noun a lack of desire to move, a lack of ability to do anything
- noun a physical force which makes a stationary body remain still, or a moving body remain moving
- noun a lack of energy, laziness
- noun the tendency of a body at rest to stay at rest or of a moving body to continue moving in a straight line unless acted on by an outside force
- The tendency of a body at rest to remain at rest, or of a body in motion to remain in motion in a straight line unless directly influenced by an external force.