nitwitted

from WordNet (r) 3.0 (2006)

nitwitted
    adj 1: (of especially persons) lacking sense or understanding or
           judgment [syn: {nitwitted}, {senseless}, {soft-witted},
           {witless}]

from Moby Thesaurus II by Grady Ward, 1.0

29 Moby Thesaurus words for "nitwitted":
      beetleheaded, blockheaded, blunderheaded, boneheaded, brainless,
      cabbageheaded, chowderheaded, chuckleheaded, clodpated, dumbheaded,
      dunderheaded, fatheaded, foolish, jolterheaded, joltheaded,
      knuckleheaded, lunkheaded, mindless, muttonheaded, numskulled,
      pumpkin-headed, sapheaded, senseless, silly, stupidheaded, unwitty,
      weak-minded, witless, woodenheaded