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flatworm vs. roundworm

[flat-wurm] / ˈflætˌwɜrm /

noun

  1. any worm of the phylum Platyhelminthes, having bilateral symmetry and a soft, solid, usually flattened body, including the planarians, tapeworms, and trematodes; platyhelminth.

[round-wurm] / ˈraʊndˌwɜrm /

noun

  1. any nematode, especially Ascaris lumbricoides, that infests the intestine of humans and other mammals.