any parasitic or free-living invertebrate of the phylum Platyhelminthes, including planarians, flukes, and tapeworms, having a flattened body with no circulatory system and only one opening to the intestine
WordReference Random House Unabridged Dictionary of American English © 2025
flat•worm
(flat′wûrm′),USA pronunciation n.
- Invertebratesany worm of the phylum Platyhelminthes, having bilateral symmetry and a soft, solid, usually flattened body, including the planarians, tapeworms, and trematodes;
platyhelminth.
- flat1 + worm 1895–1900
Collins Concise English Dictionary © HarperCollins Publishers::
'flatworm' also found in these entries (note: many are not synonyms or translations):
Chinese liver fluke
- cestode
- fluke
- planarian
- platyhelminth
- polyclad
- rhabdocoele
- tapeworm
- trematode
- turbellarian