/ Dictionary / Index T trapezoidal rule: Meaning and Definition of Find definitions for: trap'ezoi'dal rule' Pronunciation: [key] — Math. Math. a numerical method for evaluating the area between a curve and an axis by approximating the area with the areas of trapezoids. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. trapezoid Trappe, La Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language