/ Dictionary / Index E extremely high frequency: Meaning and Definition of Find definitions for: extreme'ly high' fre'quency Pronunciation: [key] — Radio. Radio. any frequency between 30 and 300 gigahertz. Abbr.: EHF, ehf Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. extremely extremely low frequency Related Content Daily Word Quiz: sinister Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language