/ Dictionary / Index H hypophosphorous: Meaning and Definition of Find definitions for: hy•po•phos•phor•ous Pronunciation: (hī"pu-fos'fur-us, -fos-fôr'us, -fōr'-), [key] — adj. of or derived from hypophosphorous acid. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. hypophosphoric acid hypophosphorous acid Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language