The Collaborative International Dictionary of English v.0.48:

Fluffy \Fluff"y\, a. [Compar. Fluffier; superl. Fluffiest.]
   Pertaining to, or resembling, fluff or nap; soft and downy.
   "The carpets were fluffy." --Thackeray.
   [1913 Webster]

         The present Barnacle . . . had a youthful aspect, and
         the fluffiest little whisker, perhaps, that ever was
         seen.                                    --Dickens.
   -- Fluff"i*ness, n.
   [1913 Webster] Flugel

WordNet (r) 3.0 (2006):

fluffy
    adj 1: like down or as soft as down [syn: downy, downlike,
           flossy, fluffy]