Source : Webster's Revised Unabridged Dictionary (1913)

Dandy \Dan"dy\, n.; pl. {Dandies}. [Cf. F. dandin, ninny, silly
   fellow, dandiner to waddle, to play the fool; prob. allied to
   E. dandle. Senses 2&3 are of uncertain etymol.]
   1. One who affects special finery or gives undue attention to
      dress; a fop; a coxcomb.

   2. (Naut.)
      (a) A sloop or cutter with a jigger on which a lugsail is
          set.
      (b) A small sail carried at or near the stern of small
          boats; -- called also {jigger}, and {mizzen}.

   3. A dandy roller. See below.

   {Dandy brush}, a yard whalebone brush.

   {Dandy fever}. See {Dengue}.

   {Dandy line}, a kind of fishing line to which are attached
      several crosspieces of whalebone which carry a hook at
      each end.

   {Dandy roller}, a roller sieve used in machines for making
      paper, to press out water from the pulp, and set the
      paper.

Source : WordNet®

dandy
     adj : very good; "he did a bully job"; "a neat sports car"; "had a
           great time at the party"; "you look simply smashing"
           [syn: {bang-up}, {bully}, {corking}, {cracking}, {great},
            {groovy}, {keen}, {neat}, {nifty}, {not bad(p)}, {peachy},
            {slap-up}, {swell}, {smashing}]
     [also: {dandiest}, {dandier}]

dandy
     n : a man who is much concerned with his dress and appearance
         [syn: {dude}, {fop}, {gallant}, {sheik}, {beau}, {swell},
          {fashion plate}, {clotheshorse}]
     [also: {dandiest}, {dandier}]