globulinPronunciation: /ˈglɒbjʊlɪn/Definition of globulin noun Biochemistry any of a group of simple proteins soluble in salt solutions and forming a large fraction of blood serum protein. Origin: mid 19th century: from globule (in the archaic sense 'blood corpuscle') + -in1globulin in other Oxford dictionaries Definition of globulin in the US English dictionary