/ Dictionary / Index P phytonadione: Meaning and Definition of Find definitions for: phy•to•na•di•one Pronunciation: (fī"tō-nu-dī'ōn), [key] — n. Biochem. See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: phytonadione (Thesaurus) phyton phytopathology Related Content Daily Word Quiz: jovial Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language