The state or quality of being inert, or destitute of the power to move per se; that quality of passiveness by which bodies persist in a state of rest, or of motion given to them by external force. In the language of philosophy, this quality is called vis inertioe, or inertia.

Want of activity or exertion; habitual indisposition to action or motion; sluggishness. In esse, in being; actually existing; distinguished from in posse, or in potentia, which denote that a thing is not, but may be.