grand·moth·er·ly (gr?nd?m?th??r-l?, gr?n?-)adj.1. Characteristic of or befitting a grandmother.2. Having the qualities of a grandmother.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.grandmotherly (??ræn?m?ð?l?; ??rænd-) adjof, resembling, or suitable to a grandmother, esp in being protective, indulgent, or solicitousCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014