unintelligent

from WordNet (r) 3.0 (2006)

unintelligent
    adj 1: lacking intelligence; "a dull job with lazy and
           unintelligent co-workers" [syn: {unintelligent},
           {stupid}] [ant: {intelligent}]

from The Collaborative International Dictionary of English v.0.48

Unintelligent \Unintelligent\
   See {intelligent}.

from Moby Thesaurus II by Grady Ward, 1.0

81 Moby Thesaurus words for "unintelligent":
      artless, awkward, blankminded, brainless, callow, dumb, empty,
      empty-headed, fatuous, foolish, gauche, green, groping, half-assed,
      headless, ignorant, inadept, inane, inapt, inattentive,
      inefficient, inept, inexperienced, inexpert, innocent, insensate,
      irrational, know-nothing, lackbrained, lean-minded, lean-witted,
      mediocre, mindless, naive, nescient, not bright, of little brain,
      pea-brained, pedestrian, pin-brained, poor, raw, reasonless,
      senseless, simple, skill-less, slackminded, slackwitted,
      strange to, tentative, thoughtless, unacquainted, unapprized,
      unapt, uncomprehending, unconversant, undeft, undexterous,
      undextrous, unenlightened, unfacile, unfamiliar, ungifted,
      unilluminated, uninformed, uninitiated, unintellectual, unknowing,
      unposted, unproficient, unreasoning, unripe, unskillful, unsure,
      untalented, unthinking, unversed, unwise, vacuous, weak, witless