Vermiform

Dicyema, a small parasite typically described as "vermiform"

Vermiform describes something shaped like a worm. The expression is often employed in biology and anatomy to describe more or less tubular or cylindrical, usually soft body parts or animals. The word root is Latin, vermes-worms and formes-shaped. A well known example is the vermiform appendix, a small, blind section of the gut in humans and a number of other mammals.

A number of soft-bodied animal phyla are typically described as vermiform. The more well known one are undoubtedly the annelids (earthworm and relatives) and the roundworms (a very common, mainly parasitic group), but a number of less well known phyla answer to the same description. Examples range from the minute parasitic mesozoans to the larger bodied free-living phyla like ribbon worms, peanut worms and priapulids.