Chae*top"o*da (?), n. pl. [NL., from Gr. hair + -poda.] Zool.
A very extensive order of Annelida, characterized by the presence of lateral setae, or spines, on most or all of the segments. They are divided into two principal groups: Oligochaeta, including the earthworms and allied forms, and Polychaeta, including most of the marine species.
© Webster 1913.