[1] : The Collaborative International Dictionary of English v.0.48

wistful \wist"ful\, a. for wishful; perhaps influenced by
   wistly, which is probably corrupted from oe. wisly certainly
   from icel. viss certain, akin to e. wit. see wish.
   1913 webster
   1. longing; wishful; desirous.
      1913 webster

            lifting up one of my sashes, i cast many a wistful,
            melancholy look towards the sea.      --swift.
      1913 webster

   2. full of thought; eagerly attentive; meditative; musing;
      pensive; contemplative.
      1913 webster

            that he who there at such an hour hath been,
            will wistful linger on that hallowed spot. --byron.
      1913 webster -- wist"fully, adv. -- wist"fulness,
      n.
      1913 webster
see also:
wish wist"fully wist"fulness 

[2] : WordNet (r) 2.0

wistful
     adj 1: full of longing or unfulfilled desire; "those wistful little
            ads that the lovelorn place in the classifieds" syn:
            yearning
     2: showing pensive sadness; "the sensitive and wistful response
        of a poet to the gentler phases of beauty" syn: pensive
see also:
yearning pensive 

[3] : Moby Thesaurus II by Grady Ward, 1.0

72 moby thesaurus words for "wistful":
   ashamed, atrabiliar, atrabilious, blue, cogitative, cognitive,
   concentrating, concentrative, conceptive, conceptual,
   conceptualized, conscience-smitten, conscience-stricken,
   contemplating, contemplative, deliberating, deliberative,
   excogitating, full of remorse, funky, hankering, homesick, honing,
   ideative, introspective, languishing, longing, meditating,
   meditative, melancholic, melancholy, mental, museful, musing,
   noetic, nostalgic, pensive, pining, pondering, prehensive,
   reflecting, reflective, regretful, remorseful, repining, rueful,
   ruminant, ruminating, ruminative, self-accusing, self-condemning,
   self-convicting, self-debasing, self-flagellating,
   self-humiliating, self-punishing, self-reproaching, serious,
   shamefaced, shamefast, shameful, sober, sorry, speculative,
   thinking, thought, thoughtful, tristful, unhappy about, wishful,
   yearnful, yearning

Wistful >> W Words
Wistful, definition of term: Wistful
wistful_pag1.html