/ Dictionary / Index U uranium oxide: Meaning and Definition of Find definitions for: ura'nium ox'ide Pronunciation: [key] — Chem. Chem. any of the compounds of uranium and oxygen, as UO, UO, UO, or UO. SeeCf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. uranium hexafluoride uranium series Related Content Daily Word Quiz: nefarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language