The Collaborative International Dictionary of English v.0.48:

Sycophantic \Syc`o*phan"tic\, Sycophantical \Syc`o*phan"tic*al\,
   a. [Cf. Gr. ? slanderous.]
   Of or pertaining to a sycophant; characteristic of a
   sycophant; meanly or obsequiously flattering; courting favor
   by mean adulation; parasitic.
   [1913 Webster]

         To be cheated and ruined by a sycophantical parasite.
                                                  --South.
   [1913 Webster]

         Sycophantic servants to the King of Spain. --De
                                                  Quincey.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sycophantic
    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]