Breadcrumb Home > Dictionary > Index R Ru: Meaning and Definition of Find definitions for: Ru Pronunciation: [key] — Symbol, Chem. ruthenium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ru (Thesaurus) rtw RU 486 ✖ Related Content Daily Word Quiz: nomdeguerre Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language