Definition of peristomium in English:

peristomium

noun

  • Zoology. The first true somite of certain annelids (such as earthworms), bearing the mouth.

Origin

Early 19th century (in an earlier sense). From peri- + ancient Greek στόμα mouth + classical Latin -ium.

Pronunciation

peristomium

/ˌpɛrɪˈstəʊmɪəm/