/ Dictionary / Index S selenious: Meaning and Definition of Find definitions for: se•le•ni•ous Pronunciation: (si-lē'nē-us), [key] — adj. Chem. containing tetravalent or bivalent selenium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. seleniferous selenious acid Related Content Daily Word Quiz: resilient Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language