WordNet (r) 3.0 (2006):

ACE inhibitor
    n 1: an antihypertensive drug that blocks the formation of
         angiotensin II in the kidney, leading to relaxation of the
         arteries; promotes the excretion of salt and water by
         inhibiting the activity of the angiotensin converting
         enzyme; also used to treat congestive heart failure [syn:
         ACE inhibitor, angiotensin-converting enzyme inhibitor]