inertness, especially with regard to effort, motion, action, and the like; inactivity; sluggishness.
Physics. the property of matter by which it retains its state of rest or its velocity along a straight line so long as it is not acted upon by an external force. an analogous property of a force: electric inertia.
Medicine/Medical. lack of activity, especially as applied to a uterus during childbirth when its contractions have decreased or stopped.
the state of being inert; disinclination to move or act
(physics) the tendency of a body to preserve its state of rest or uniform motion unless acted upon by an external force an analogous property of other physical quantities that resist change: thermal inertia