grand·moth·er (gr?nd?m?th??r, gr?n?-)n.1. The mother of one’s father or mother.2. A female ancestor.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.grandmother (??ræn?m?ð?; ??rænd-) n1. the mother of one’s father or mother2. (often plural) a female ancestor3. (often capital) a familiar term of address for an old woman4. teach one’s grandmother to suck eggs See egg18Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014grand?moth?er (?græn?m?ð ?r, ?grænd-, ?græm-) n. 1. the mother of one’s father or mother. 2. a female ancestor. [1375?1425] grand?moth`er?ly, adj. grand?moth`er?li?ness, n. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.