Guise (g?z) French noble family including Francis of Lorraine, Second Duke of Guise (1519-1563), a military leader who defeated Holy Roman Emperor Charles V and battled the Huguenots. His son Henry of Lorraine, Third Duke of Guise (1550-1588), helped plan the St. Bartholomews’ Day massacre of Huguenots in 1572 and was later assassinated by order of Henry III.guise (g?z)n.1. Outward appearance or aspect; semblance.2. False appearance; pretense: spoke to me under the guise of friendship.3. Mode of dress; garb: huddled on the street in the guise of beggars.4. Obsolete Custom; habit.[Middle English, manner, fashion, from Old French, of Germanic origin; see weid- in Indo-European roots.]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.guise (?a?z) n1. semblance or pretence: under the guise of friendship. 2. external appearance in general3. (Clothing & Fashion) archaic manner or style of dress4. obsolete customary behaviour or mannervb5. dialect to disguise or be disguised in fancy dress6. (tr) archaic to dress or dress up[C13: from Old French guise, of Germanic origin; see wise2]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014guise (ga?z) n., v. guised, guis?ing. n. 1. general external appearance; aspect; semblance. 2. assumed appearance or mere semblance: an intrusive question asked in the guise of friendship. 3. style of dress. 4. Archaic. manner; mode. v.t. 5. to dress; attire. [1175?1225; Middle English g(u)ise