platyhelminthes

As a proper noun platyhelminthes

is .

As a noun starfish is

any of various asteroids or other echinoderms (not in fact fish) with usually five arms, many of which eat bivalves or corals by everting their stomach.

Platyhelminthes is often a misspelling of platyhelminth.

Platyhelminthes has no English definition.

As a noun platyhelminth is

any flatworm of the phylum Platyhelminthes