Emily Dickinson Lexicon

IN-ERT'NESS, n.

1. 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 inertiæ, or inertia. Newton.
2. Want of activity or exertion; habitual indisposition to action or motion; sluggishness.