PROTHROMBIN Scrabble 20 Words With Friends 23 Scrabble letter values: P3R1O1T1H4R1O1M3B3I1N1 = 20 Definition noun a protein in blood plasma that is the inactive precursor of thrombin. — synonyms: factor_II See all 243 words you can make from PROTHROMBIN → 11-letter words Words starting with P Words ending with N ← Unscramble different letters