haematinEnglishOxford Dictionary of Englishhaematin /ˈhiːmətɪn / (US English hematin) ▸ noun [mass noun] Biochemistry a bluish-black compound derived from haemoglobin by removal of the protein part and oxidation of the iron atom. – ORIGIN mid 19th century: from Greek haima, haimat- ‘blood’ + -in1.