"flatworm." YourDictionary, n.d. Web. 19 September 2018. <http://www.yourdictionary.com/flatworm>.
flatworm. (n.d.). Retrieved September 19th, 2018, from http://www.yourdictionary.com/flatworm
Any of various parasitic and nonparasitic worms of the phylum Platyhelminthes, such as a tapeworm or a planarian, characteristically having a soft, flat, bilaterally symmetrical body and no body cavity. Also called platyhelminth .