/ Dictionary / Index H harmonic progression: Meaning and Definition of Find definitions for: harmon'ic progres'sion Pronunciation: [key] — Math. Math. a series of numbers the reciprocals of which are in arithmetic progression. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. harmonicon harmonics Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language