What is "bladder worms"

Measles \Mea"sles\, n.; pl. in form, but used as singular in senses 1, 2, & 3. [D. mazelen; akin to G. masern, pl., and E. mazer, and orig. meaning, little spots. See Mazer.]

1. (Med.) A contagious viral febrile disorder commencing with catarrhal symptoms, and marked by the appearance on the third day of an eruption of distinct red circular spots, which coalesce in a crescentic form, are slightly raised above the surface, and after the fourth day of the eruption gradually decline; rubeola. It is a common childhood disease.

   Measles commences with the ordinary symptoms of fever.
   --Am. Cyc.

2. (Veter. Med.) A disease of cattle and swine in which the flesh is filled with the embryos of different varieties of the tapeworm.

3. A disease of trees. [Obs.]

4. pl. (Zo["o]l.) The larv[ae] of any tapeworm ( T[ae]nia) in the cysticerus stage, when contained in meat. Called also bladder worms.

   German measles A mild contagious viral disease, which may cause birth defects if contracted by a pregnant woman during early pregnancy; also called rubella.