Definition of pessulus in US English:

pessulus

noun

Zoology
  • In some birds: a cartilaginous or bony bar at the junction of the bronchi, forming part of the syrinx.

Origin

Early 19th century (in an earlier sense). From classical Latin pessulus a bolt from ancient Greek πάσσαλος (Attic πάτταλος): see passalid [noun].

Pronunciation

pessulus

/ˈpɛsjʊləs/