Definition of "inertia" in English

noun

1. (physics, uncountable or countable) The property of a body that resists any change to its uniform motion; equivalent to its mass.

2. (figuratively) In a person, unwillingness to take action.

3. (medicine) Lack of activity; sluggishness; said especially of the uterus, when, in labour, its contractions have nearly or wholly ceased.