n. a synthetic analog of the pituitary hormone vasopressin that, among other functions, stimulates water retention. Desmopressin is used in pill form or in the form of a nasal spray to treat nocturnal enuresis (bed-wetting) and diabetes insipidus. It possesses more antidiuretic activity (i.e., prevents excessive water loss from the body) and less potential to raise blood pressure than vasopressin. U.S. trade name (among others): DDAVP.