/ Dictionary / Index U uranyl: Meaning and Definition of Find definitions for: u•ra•nyl Pronunciation: (yoor'u-nil), [key] — n. Chem. the bivalent ion UO, or the group UO, which forms salts with acids. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: uranyl (Thesaurus) Uranus Urartian Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language