What is "bladder worm"

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.] (Zo["o]l.) 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).

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.

n. encysted saclike larva of the tapeworm