somatomedin Syllabification: (so·mat·o·me·din)Pronunciation: /səˌmatəˈmēdn, ˌsōmə-/Definition of somatomedin noun Biochemistry a hormone that acts as an intermediate in the stimulation of tissue growth by growth hormone. Origin: 1970s: from somato- 'of the body' + (inter)med(iary) + -in1somatomedin in other Oxford dictionaries Definition of somatomedin in the British & World English dictionary