non·po·lar (n?n-p??l?r)adj.1. Not characterized by a dipole: a nonpolar covalent bond.2. Not ionizing when dissolved in water.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.nonpolar (?n?n?p??l?) adj (Chemistry) chem (of a molecule) not having a permanent dipole momentCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014