oxyhaemoglobinPronunciation: /ˌɒksɪhiːməˈgləʊbɪn/ (US oxyhemoglobin)Definition of oxyhaemoglobin noun [mass noun] Biochemistry a bright red substance formed by the combination of haemoglobin with oxygen, present in oxygenated blood. oxyhaemoglobin in other Oxford dictionaries Definition of oxyhaemoglobin in the US English dictionary