Mesozoans

Part of speech: noun

Definitions

1. Tiny parasitic aquatic animals made of only a few cells, found living inside or on marine invertebrates such as squid and octopuses
2. Minute wormlike organisms that live as parasites within the bodies of sea creatures and are placed between protozoans and metazoans
3. Microscopic simple multicellular animals that inhabit the tissues of marine hosts and form a distinct group in classifications of invertebrate life

Etymology: "Mesozoans" is the plural of "mesozoan", an animal belonging to the group Mesozoa. The name Mesozoa combines the Greek "mesos", meaning "middle", with "zoon", meaning "animal", so the group was named for animals thought to sit between two larger categories of life. The English suffix "-an" marks a member of that group, the same ending found in words like "Hawaiian" or "Lutheran".