/ Dictionary / Index P pentahydroxy: Meaning and Definition of Find definitions for: pen•ta•hy•drox•y Pronunciation: (pen"tu-hī-drok'sē), [key] — adj. Chem. (of a molecule) containing five hydroxyl groups. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pentahydric pentalpha Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language