/ Dictionary / Index U ultrahigh: Meaning and Definition of Find definitions for: ul•tra•high Pronunciation: (ul"tru-hī'), [key] — adj. extremely high: ultrahigh skyscrapers of 100 stories. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ultrafiltrate ultrahigh frequency Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language