mystery playn. A medieval drama based on scriptural events especially in the life of Jesus.[From mystery.]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.mystery play n (Theatre) (in the Middle Ages) a type of drama based on the life of Christ. Compare miracle play Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014mys?tery play` n. a medieval drama based on a Bible story, usu. about Christ. Compare miracle play, morality play. [1850?55] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.