Definition of pentacrinoid in US English:

pentacrinoid

adjective

Zoology
  • Designating a larval stage of a crinoid at which it resembles a crinoid of the genus Pentacrinus in having a stalk and a calyx consisting of five plates.

noun

Zoology
  • A larval crinoid which resembles a crinoid of the genus Pentacrinus.

Origin

Mid 19th century; earliest use found in Proceedings of the Royal Society of London. From scientific Latin Pentacrinus + -oid, perhaps after crinoid.

Pronunciation

pentacrinoid

/pɛnˈtakrɪnɔɪd/