The Collaborative International Dictionary of English v.0.48:

Catchy \Catch"y\, a.
   1. Apt or tending to catch the fancy or attention; catching;
      taking; as, catchy music.
      [Webster 1913 Suppl.]

   2. Tending to catch or insnare; entangling; -- usually used
      fig.; as, a catchy question.
      [Webster 1913 Suppl.]

   3. Consisting of, or occuring in, disconnected parts or
      snatches; changeable; as, a catchy wind.
      [Webster 1913 Suppl.]

            It [the fox's scent] is . . . flighty or catchy, if
            variable.                             --Encyc. of
                                                  Sport.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

catchy
    adj 1: having concealed difficulty; "a catchy question"; "a
           tricky recipe to follow" [syn: catchy, tricky]
    2: likely to attract attention; "a catchy title for a movie"
       [syn: attention-getting, catchy]