The Collaborative International Dictionary of English v.0.48:

Flattery \Flat"ter*y\, n.; pl. Flatteries. [OE. flaterie, OF.
   flaterie, F. flaterie, fr. flater to flatter, F. flatter; of
   uncertain origin. See Flatter, v. t.]
   The act or practice of flattering; the act of pleasing by
   artful commendation or compliments; adulation; false,
   insincere, or excessive praise.
   [1913 Webster]

         Just praise is only a debt, but flattery is a present.
                                                  --Rambler.
   [1913 Webster]

         Flattery corrupts both the receiver and the giver.
                                                  --Burke.

   Syn: Adulation; compliment; obsequiousness. See Adulation.
        [1913 Webster]

WordNet (r) 3.0 (2006):

flattery
    n 1: excessive or insincere praise