The Collaborative International Dictionary of English v.0.48:

Deludable \De*lud"a*ble\, a.
   Capable of being deluded; liable to be imposed on; gullible.
   --Sir T. Browne.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

19 Moby Thesaurus words for "deludable":
   cullible, deceivable, dupable, easy, exploitable, foolable, green,
   gullible, hoaxable, hoodwinkable, humbugable, ingenuous, naive,
   persuadable, seduceable, simple, soft, unsophisticated,
   victimizable