/ Dictionary / Index R roentgenopaque: Meaning and Definition of Find definitions for: roent•gen•o•paque Pronunciation: (rent"gu-nō-pāk', -ju-, runt"-), [key] — adj. not permitting the passage of x-rays. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. roentgenometer roentgenoparent Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language