/ Dictionary / Index M moment of inertia: Meaning and Definition of Find definitions for: mo'ment of iner'tia Pronunciation: [key] the sum of the products of the mass and the square of the perpendicular distance to the axis of rotation of each particle in a body rotating about an axis. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. momento moment of momentum Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language