/ Dictionary / Index R rubious: Meaning and Definition of Find definitions for: ru•bi•ous Pronunciation: (r'bē-us), [key] — adj. ruby-colored. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Rubinstein ruble Related Content Daily Word Quiz: acme Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language