/ Dictionary / Index U ultrapure: Meaning and Definition of Find definitions for: ul•tra•pure Pronunciation: (ul"tru-pyoor'), [key] — adj. extremely pure, esp. without impurities: ultrapure silicon for semiconductors. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ultranet ultrared Related Content Daily Word Quiz: inane Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language