moment of inertia

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A measure of a body's resistance to angular acceleration, equal to:
2. n. The product of the mass of a particle and the square of its distance from a reference.
3. n. The sum of the products of each mass element of a body multiplied by the square of its distance from an axis.
4. n. The sum of the products of each element of an area multiplied by the square of its distance from a coplanar axis.

Wiktionary

1. n. physics A measure of a body's resistance to a change in its angular rotation velocity
2. n. engineering A measure of a body's resistance to bending; second moment of inertia; second moment of area.

GNU Webster's 1913

1. n. of a rotating body, the sum of the mass of each particle of matter of the body into the square of its distance from the axis of rotation; -- called also moment of rotation and moment of the mass.

WordNet 3.0

1. n. the tendency of a body to resist angular acceleration