calcium channel blockern. Any of a class of drugs that inhibit the movement of calcium ions across the cell membranes of cardiac and smooth muscle and are used to treat cardiovascular disorders.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.calcium channel blocker n (Medicine) any drug that prevents the influx of calcium ions into cardiac and smooth muscle: used to treat high blood pressure and angina. Also called: calcium antagonist Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014