Definition of narcomedusan in US English:

narcomedusan

noun

Zoology
  • A jellyfish of the suborder Narcomedusae.

adjective

Zoology
  • Of or relating to the suborder Narcomedusae.

Origin

Late 19th century; earliest use found in George Rolleston (1829–1881), physician and physiologist. From Narcomedusae + -an, after medusan.