1. In Polychaeta, usually biramous, muscular, lateral projections of the body, paired and extending from the body segments, more or less compressed laterally, and bearing setae; in free-swimming forms they are used for locomotion, and in sessile forms to fan water.
2. In opisthobranch Mollusca, lateral projections from the side of the foot which form fins used in swimming.
"parapodia." A Dictionary of Zoology. . Encyclopedia.com. (August 15, 2018). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/parapodia
"parapodia." A Dictionary of Zoology. . Retrieved August 15, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/parapodia