neurohypophysisPronunciation: /ˌnjʊərəʊhʌɪˈpɒfɪsɪs/Definition of neurohypophysis noun (plural neurohypophyses /-siːz/) Anatomy the posterior lobe of the hypophysis (pituitary gland), which stores and releases oxytocin and vasopressin produced in the hypothalamus. neurohypophysis in other Oxford dictionaries Definition of neurohypophysis in the US English dictionary