The Collaborative International Dictionary of English v.0.48:

Noetic \No*et"ic\, Noetical \No*et"ic*al\, a. [Gr. ?, fr. ? to
   perceive, ? mind, intellect.]
   Of or pertaining to the intellect; intellectual.
   [1913 Webster]

         I would employ the word noetic to express all those
         cognitions which originate in the mind itself. --Sir W.
                                                  Hamilton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

noetic
    adj 1: of or associated with or requiring the use of the mind;
           "intellectual problems"; "the triumph of the rational
           over the animal side of man" [syn: intellectual,
           rational, noetic]

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "noetic":
   bright, cerebral, cogitative, cognitive, concentrating,
   concentrative, conceptive, conceptual, conceptualized,
   contemplating, contemplative, deliberating, deliberative,
   discursive, endopsychic, excogitating, ideational, ideative,
   intellectual, intelligent, internal, introspective, knowing,
   meditating, meditative, mental, museful, musing, noological,
   not so dumb, pensive, phrenic, pondering, prehensive, psychic,
   psychologic, rational, reasonable, reasoning, reflecting,
   reflective, ruminant, ruminating, ruminative, sane, sensible,
   serious, sober, sophic, speculative, spiritual, strong-minded,
   subjective, thinking, thought, thoughtful, understanding,
   wistful