/ Dictionary / Index U U-239: Meaning and Definition of Find definitions for: U-239 Pronunciation: [key] — Chem. Chem. See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. U-238 U.A.E. Related Content Daily Word Quiz: lyceum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language