The Collaborative International Dictionary of English v.0.48:

Cysticerce \Cys"ti*cerce\ (s?s"t?-s?rs), Cysticercus
\Cys`ti*cer"cus\ (-s?r"k?s), n. [NL. cysticercus, fr. Gr. ????
   bladder + ke`rkos tail: cf. F. cysticerque.] (Zool.)
   The larval form of a tapeworm, having the head and neck of a
   tapeworm attached to a saclike body filled with fluid; --
   called also bladder worm, hydatid, and measle (as, pork
   measle).
   [1913 Webster]

   Note: These larvae live in the tissues of various living
         animals, and, when swallowed by a suitable carnivorous
         animal, develop into adult tapeworms in the intestine.
         See Measles, 4, Tapeworm.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bladder \Blad"der\ (bl[a^]d"d[~e]r), n. [OE. bladder, bleddre,
   AS. bl[=ae]dre, bl[=ae]ddre; akin to Icel. bla[eth]ra, SW.
   bl[aum]ddra, Dan. bl[ae]re, D. blaar, OHG. bl[=a]tara the
   bladder in the body of animals, G. blatter blister, bustule;
   all fr. the same root as AS. bl[=a]wan, E. blow, to puff. See
   Blow to puff.]
   [1913 Webster]
   1. (Anat.) A bag or sac in animals, which serves as the
      receptacle of some fluid; as, the urinary bladder; the
      gall bladder; -- applied especially to the urinary
      bladder, either within the animal, or when taken out and
      inflated with air.
      [1913 Webster]

   2. Any vesicle or blister, especially if filled with air, or
      a thin, watery fluid.
      [1913 Webster]

   3. (Bot.) A distended, membranaceous pericarp.
      [1913 Webster]

   4. Anything inflated, empty, or unsound. "To swim with
      bladders of philosophy." --Rochester.
      [1913 Webster]

   Bladder nut, or Bladder tree (Bot.), a genus of plants
      (Staphylea) with bladderlike seed pods.

   Bladder pod (Bot.), a genus of low herbs (Vesicaria) with
      inflated seed pods.

   Bladdor senna (Bot.), a genus of shrubs (Colutea), with
      membranaceous, inflated pods.

   Bladder worm (Zool.), the larva of any species of tapeworm
      (T[ae]nia), found in the flesh or other parts of
      animals. See Measle, Cysticercus.

   Bladder wrack (Bot.), the common black rock weed of the
      seacoast (Fucus nodosus and Fucus vesiculosus) --
      called also bladder tangle. See Wrack.
      [1913 Webster]

WordNet (r) 3.0 (2006):

bladder worm
    n 1: encysted saclike larva of the tapeworm