dap·per (d?p??r)adj.1. a. Neatly dressed; trim.b. Very stylish in dress.2. Lively and alert.[Middle English daper, elegant, probably from Middle Dutch dapper, quick, strong.]dap?per·ly adv.dap?per·ness n.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.dapper (?dæp?) adj1. neat and spruce in dress and bearing; trim2. small and nimble[C15: from Middle Dutch: active, nimble] ?dapperly adv ?dapperness nCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014dap?per (?dæp ?r) adj. 1. neat, trim, or smart in dress or demeanor; spruce. 2. lively and brisk: to walk with a dapper step. 3. small and active. [1400?50; late Middle English daper