Inertia is a term used to describe the resistance of an object to any changes in motion. It can also be referred to as an object's tendency to remain stationary or in motion with a consistent speed and direction. Several synonyms can be used interchangeably for the word "inertia," including inactivity, immobility, lethargy, sluggishness, slothfulness, torpor, and stasis. These synonyms are often used to describe a lack of movement, energy, or motivation. Whether it be an object, a person, or a situation, inertia can inhibit progress and hinder productivity, requiring a force or external stimuli to overcome and initiate change.