/ Dictionary / Index C common difference: Meaning and Definition of Find definitions for: com'mon dif'ference Pronunciation: [key] — Math. Math. the difference between any two consecutive terms in an arithmetic progression. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. common denominator common disaster Related Content Daily Word Quiz: loathe Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language