epistome
/ˈɛpɪstoʊm/
noun
- A plate or structure covering the mouth or front part of the body in some invertebrates, such as certain worms and crustaceans.
- The biologist examined the epistome of the marine worm under a microscope.
- The epistome of the barnacle is a small, hard plate near its opening.
- In some crustaceans, the epistome helps protect the mouthparts.