- any of various flat or tapelike worms of the class Cestoidea, lacking an alimentary canal, and parasitic when adult in the alimentary canal of humans and other vertebrates: the larval and adult stages are usually in different hosts.
- any parasitic ribbon-like flatworm of the class Cestoda, having a body divided into many egg-producing segments and lacking a mouth and gut. The adults inhabit the intestines of vertebrates
