/vas'oh pres"in/ , n.
1. Biochem. a peptide hormone, synthesized in the hypothalamus and released by the posterior pituitary gland, that stimulates capillary muscles and reduces the flow of urine and increases its concentration.
2. Pharm. a synthetic preparation of this hormone, used as an antidiuretic in the treatment of diabetes insipidus. Also called antidiuretic hormone, ADH .
[ 1928; orig. trademark ]