The Collaborative International Dictionary of English v.0.48:

Fawn \Fawn\, v. i. [imp. & p. p. Fawned; p. pr. & vb. n.
   Fawning.] [OE. fawnen, fainen, fagnien, to rejoice,
   welcome, flatter, AS. f[ae]gnian to rejoice; akin to Icel.
   fagna to rejoice, welcome. See Fain.]
   To court favor by low cringing, frisking, etc., as a dog; to
   flatter meanly; -- often followed by on or upon.
   [1913 Webster]

         You showed your teeth like apes, and fawned like
         hounds.                                  --Shak.
   [1913 Webster]

         Thou with trembling fear,
         Or like a fawning parasite, obeyest.     --Milton.
   [1913 Webster]

         Courtiers who fawn on a master while they betray him.
                                                  --Macaulay.
   [1913 Webster]

WordNet (r) 3.0 (2006):

fawning
    adj 1: attempting to win favor from influential people by
           flattery [syn: bootlicking, fawning, obsequious,
           sycophantic, toadyish]
    2: attempting to win favor by flattery [syn: bootlicking,
       fawning, sycophantic, toadyish]

Moby Thesaurus II by Grady Ward, 1.0:

111 Moby Thesaurus words for "fawning":
   abject, adulation, adulatory, apple-polishing, ass-kissing,
   backscratching, beggarly, bland, blandishing, blandishment,
   blarney, blarneying, bootlicking, brown-nosing, bunkum, buttery,
   cajolement, cajolery, cajoling, compliant, compliment,
   complimentary, courtierly, courtly, cowering, crawling, cringing,
   crouching, deferential, envious, eyewash, fair words, fair-spoken,
   fawnery, fine-spoken, flattering, flattery, flunkyism, footlicking,
   fulsome, grease, groveling, gushing, handshaking, hangdog,
   honey-mouthed, honey-tongued, honeyed, honeyed phrases,
   honeyed words, humble, ignoble, incense, ingratiating,
   ingratiation, insincere, insinuating, insinuation, kowtowing,
   mealy-mouthed, mealymouthed, mealymouthedness, mean, obeisance,
   obeisant, obsequious, obsequiousness, oil, oily, oily-tongued,
   on bended knee, palaver, parasitic, parasitism, praise,
   pretty lies, prostrate, prostration, servile, slavish, slimy,
   slobbery, smarmy, smooth, smooth-spoken, smooth-tongued, sniveling,
   soap, soapy, soft soap, soft-soaping, spineless, sponging,
   submissive, subservient, sweet nothings, sweet talk, sweet words,
   sycophancy, sycophant, sycophantic, timeserving, toadeating,
   toadying, toadyish, toadyism, truckling, tufthunting, unctuous,
   wheedling, yielding