flatworm
noun
flat·worm
ˈflat-ˌwərm 
: any of a phylum (Platyhelminthes) of soft-bodied usually much flattened acoelomate worms (such as the planarians, flukes, and tapeworms)
called also platyhelminth
Examples of flatworm in a Sentence
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Two species of the flatworms were discovered in California’s freshwater fish, according to a study published Tuesday in the Journal of Infectious Diseases.
—
Karen Garcia, Los Angeles Times, 4 June 2025
The flatworms first infect the snail, then a fish, and finally a warm-blooded vertebrate, like a bird or a human, that consumes the infected fish.
—City News Service, San Diego Union-Tribune, 3 June 2025
Eventually, 11 flatworms, less than an inch long, were collected and brought back to the laboratory environment to be studied.
—Irene Wright, Miami Herald, 9 Apr. 2025
Planarians are small flatworms that would probably be living quiet lives somewhere if biologists hadn't discovered their ability to regenerate lots of adult tissues when damaged.
—John Timmer, ArsTechnica, 18 Apr. 2025
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Karen Garcia, Los Angeles Times, 4 June 2025
The flatworms first infect the snail, then a fish, and finally a warm-blooded vertebrate, like a bird or a human, that consumes the infected fish.
—City News Service, San Diego Union-Tribune, 3 June 2025
Eventually, 11 flatworms, less than an inch long, were collected and brought back to the laboratory environment to be studied.
—Irene Wright, Miami Herald, 9 Apr. 2025
Planarians are small flatworms that would probably be living quiet lives somewhere if biologists hadn't discovered their ability to regenerate lots of adult tissues when damaged.
—John Timmer, ArsTechnica, 18 Apr. 2025
See All Example Sentences for flatworm
Cite this Entry
“Flatworm.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/flatworm. Accessed 13 Jun. 2025.
Copy CitationKids Definition
flatworm
noun
flat·worm
-ˌwərm
: any of a phylum of simple worms (as planarians, flukes, or tapeworms) that have a soft flat body, lack a body cavity, and have bilateral symmetry
Medical Definition
flatworm
noun
flat·worm
ˈflat-ˌwərm
: any worm of the phylum Platyhelminthes : platyhelminth
especially
: turbellarian
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