Christ·mas·tide (kr?s?m?s-t?d?)n. A Christian festival observed from December 24, Christmas Eve, to January 5, the eve of Epiphany.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.Christmastide (?kr?sm?s?ta?d) n an archaic or literary name for Christmas3Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014Christ?mas?tide (?kr?s m?s?ta?d) n. 1. the Christmas season. 2. the period from Christmas Eve to Epiphany. [1620?30] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.