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

weasel \wea"sel\, n. oe. wesele, as. wesle; akin to d. wezel,
   g. wiesel, ohg. wisala, icel. hreyivimacsla, dan.
   vaumsel, sw. vessla; of uncertain origin; cf. gr. ?, ?,
   cat, weasel. zool.
   any one of various species of small carnivores belonging to
   the genus putorius, as the ermine and ferret. they have a
   slender, elongated body, and are noted for the quickness of
   their movements and for their bloodthirsty habit in
   destroying poultry, rats, etc. the ermine and some other
   species are brown in summer, and turn white in winter; others
   are brown at all seasons.
   1913 webster

   malacca weasel, the rasse.

   weasel coot, a female or young male of the smew; -- so
      called from the resemblance of the head to that of a
      weasel. called also weasel duck.

   weasel lemur, a short-tailed lemur lepilemur
      mustelinus. it is reddish brown above, grayish brown
      below, with the throat white.
      1913 webster
see also:
putorius malacca weasel weasel coot weasel duck weasel lemur lepilemur mustelinus 

[2] : WordNet (r) 2.0

weasel
     n : small carnivorous mammal with short legs and elongated body
         and neck

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

86 moby thesaurus words for "weasel":
   argus, cape polecat, skimobile, sno-cat, ape, avoid, back and fill,
   bar, bear, blade, blench, blink, cat, cavy, chimp, chimpanzee,
   coon, cringe, dodge, draw back, duck, eagle, equivocate, evade,
   fade, fall back, ferret, flinch, foumart, glutton, groundhog,
   guinea pig, hang back, hawk, hedge, hedgehog, hem and haw,
   hum and haw, jib, lynx, mince the truth, mince words, monk, monkey,
   mousehound, opossum, palter, parry, polecat, porcupine, possum,
   prairie dog, prevaricate, pull back, pussyfoot, quail, quill pig,
   raccoon, recoil, reel back, retreat, runner, sheer off, shrink,
   shrink back, shuffle, shy, sidestep, skunk, sled, sleigh, slink,
   sneaker, snowmobile, start aside, start back, swerve, tergiversate,
   turn aside, waffle, weasel out, whistle-pig, wince, wolverine,
   woodchuck, zoril

[4] : Jargon File (4.3.1, 29 Jun 2001)

weasel n. cambridge a naive user, one who deliberately or
   accidentally does things that are stupid or ill-advised. roughly
   synonymous with loser.


see also:
loser 

[5] : The Free On-line Dictionary of Computing (27 SEP 03)

weasel
     
         cambridge a naive user, one who deliberately
        or accidentally does things that are stupid or ill-advised.
        roughly synonymous with loser.
     
        jargon file
     
        1995-03-21
     
     
see also:
loser jargon file 

[6] : Easton's 1897 Bible Dictionary

weasel
   heb. holedh, enumerated among unclean animals lev. 11:29.
   some think that this hebrew word rather denotes the mole spalax
   typhlus common in palestine. there is no sufficient reason,
   however, to depart from the usual translation. the weasel tribe
   are common also in palestine.
   

Weasel >> W Words
Weasel, definition of term: Weasel
weasel_pag1.html