/ Dictionary / Index H harmonic interval: Meaning and Definition of Find definitions for: harmon'ic in'terval. Pronunciation: [key] See under(def. 6). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. harmonic conjugates harmonic law 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