trematode
noun
trem·a·tode ˈtre-mə-ˌtōd 
: any of a class (Trematoda) of parasitic usually hermaphroditic flatworms including the flukes
trematode adjective
Example Sentences
Recent Examples on the Web Euhaplorchis californiensis, for one, is a trematode flatworm that, in its larval stage, looks a bit like a sperm, with a big head and long tail. 
Rachel Nuwer, Scientific American, 28 Apr. 2022 Maybe there’s a reason another name for a trematode is a fluke. Sabrina Imbler, The Atlantic, 16 Feb. 2021 Take the trematode preying on the California killifish, a normally secretive bait fish that hangs out in western salt marshes. Washington Post, 14 Dec. 2020 The free-swimming trematode parasites that trigger swimmer's itch typically experience a three-host life cycle — starting with a mud snail, then a crab or a fish that will eventually be eaten by a bird. USA TODAY, 30 Sep. 2017 Periwinkle snails infected with the trematode species Cryptocotyle lingua, for instance, eat significantly less algae along their Atlantic coast homes, because the parasite weakens their digestive tracts. Ben Panko, Smithsonian, 7 Sep. 2017
Rachel Nuwer, Scientific American, 28 Apr. 2022 Maybe there’s a reason another name for a trematode is a fluke. Sabrina Imbler, The Atlantic, 16 Feb. 2021 Take the trematode preying on the California killifish, a normally secretive bait fish that hangs out in western salt marshes. Washington Post, 14 Dec. 2020 The free-swimming trematode parasites that trigger swimmer's itch typically experience a three-host life cycle — starting with a mud snail, then a crab or a fish that will eventually be eaten by a bird. USA TODAY, 30 Sep. 2017 Periwinkle snails infected with the trematode species Cryptocotyle lingua, for instance, eat significantly less algae along their Atlantic coast homes, because the parasite weakens their digestive tracts. Ben Panko, Smithsonian, 7 Sep. 2017 Word History
Etymology
ultimately from Greek trēmatōdēs pierced with holes, from trēmat-, trēma hole, from tetrainein to bore — more at throw entry 1
First Known Use
circa 1859, in the meaning defined above
Medical Definition
trematode
noun
trem·a·tode ˈtrem-ə-ˌtōd
: any parasitic flatworm (as a liver fluke) of the class Trematoda