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

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "flattery":
   accolade, adulation, apotheosis, ass-kissing, beguilement,
   bepraisement, blandishment, blarney, brown-nosing, cajolery,
   congratulation, deification, eloge, encomium, eulogium, eulogy,
   exaltation, excessive praise, glorification, glory, hero worship,
   homage, hommage, honeyed words, honor, idolatry, idolizing,
   incense, kudos, laud, laudation, lionizing, magnification,
   meed of praise, oil, overpraise, paean, panegyric, praise, soft,
   soft soap, sweet talk, tribute, truckling, wheedling