somatostatin Syllabification: (so·mat·o·stat·in)Pronunciation: /səˌmatəˈstatn, ˌsōmə-/Definition of somatostatin noun Biochemistry a hormone secreted in the pancreas and pituitary gland that inhibits gastric secretion and somatotropin release. somatostatin in other Oxford dictionaries Definition of somatostatin in the British & World English dictionary