Definition of monactinellid in US English:

monactinellid

noun

Zoology
rare
  • A monactinal sponge.

Origin

Late 19th century (in an earlier sense). From scientific Latin Monactinellida from mono- + ancient Greek ἀκτιν-, ἀκτίς ray + scientific Latin -ella + -ida.

Pronunciation

monactinellid

/mɒˌnaktɪˈnɛlɪd/