Meaning of beta blocker

be'ta block"er

Pronunciation: [key]
— Pharm. Pharm.
  1. any of various substances that interfere with the action of the beta receptors: used primarily to reduce the heart rate or force in the prevention, management, or treatment of angina, hypertension, or arrythmias.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.