Definitions

1. noun

Any of various flat, usually worm-like or soft-bodied animals, such as tapeworms, liver flukes, or planarians, that belong to the phylum Platyhelminthes.

“The doctor diagnosed the patient with a parasitic flatworm infection.”

2. noun

A simple multicellular animal, typically flat and worm-like in appearance.

“Some species of flatworms are found in aquatic environments.”