[1] : The Collaborative International Dictionary of English v.0.48

dapper \dap"per\, a. oe. daper; prob. fr. d. dapper brave,
   valiant; akin to g. tapfer brave, ohg. taphar heavy, weighty,
   oslav. dobru^ good, russ. dobrui. cf. deft.
   little and active; spruce; trim; smart; neat in dress or
   appearance; lively.
   1913 webster

         he wondered how so many provinces could be held in
         subjection by such a dapper little man.  --milton.
   1913 webster

         the dapper ditties that i wont devise.   --spenser.
   1913 webster

         sharp-nosed, dapper steam yachts.        --julian
                                                  hawthorne.
   1913 webster
see also:
deft 

[2] : WordNet (r) 2.0

dapper
     adj : marked by smartness in dress and manners; "a dapper young
           man"; "a jaunty red hat" syn: dashing, jaunty, natty,
            raffish, rakish, smart, spiffy, snappy, spruce
see also:
dashing jaunty natty raffish rakish smart 
spiffy snappy spruce 

[3] : Moby Thesaurus II by Grady Ward, 1.0

47 moby thesaurus words for "dapper":
   bandbox, braw, chic, chichi, classy, clothes-conscious,
   cosmopolitan, dashing, doggy, dressed to advantage,
   dressed to kill, dressy, elegant, exquisite, fashionable, genteel,
   jaunty, natty, neat, nifty, nobby, posh, rakish, recherche, ritzy,
   sassy, sharp, showy, sleek, smart, smug, snazzy, soigne, soignee,
   sophisticated, spiffy, spruce, style-conscious, stylish, swank,
   swanky, swell, tricksy, trig, trim, well-dressed, well-groomed

Dapper >> D Words
Dapper, definition of term: Dapper
dapper_pag1.html