/ Dictionary / Index P phosphoprotein: Meaning and Definition of Find definitions for: phos•pho•pro•tein Pronunciation: (fos"fō-prō'tēn, -tē-in), [key] — n. Biochem. a protein, as casein or ovalbumin, in which one or more hydroxyl groups of serine, threonine, or tyrosine are hydroxylated. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: phosphoprotein (Thesaurus) phosphonium iodide phosphor Related Content Daily Word Quiz: opulent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language