Tapeworms

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Cestoda \Cestoda\ n. [NL., gr. Gr. kesto`s girdle + -oid.] (Zo["o]l.) A class of parasitic worms (Platelminthes) of which the tapeworms are the most common examples. The body is flattened, and usually but not always long, and composed of numerous joints ...

Wikipedia Word definitions in Wikipedia
Cestoda ( Cestoidea ) is a class of parasitic flatworms , of the phylum Platyhelminthes . Biologists informally refer to them as cestodes. The best-known species are commonly called tapeworms . All cestodes are parasitic and their life histories vary, but ...