Definition of rhopalium in English:

rhopalium

noun

Zoology
  • In many jellyfishes: any of several small, club-shaped sensory structures (usually four or eight) that project from the margin of the umbrella, typically containing statoliths and ocelli.

Origin

Late 19th century; earliest use found in Journal of the Royal Microscopical Society. From post-classical Latin rhopalium from ancient Greek ῥόπαλον club + scientific Latin -ium.

Pronunciation

rhopalium

/rəʊˈpeɪlɪəm/