Definition of discomedusan in US English:

discomedusan

noun

Zoology
  • A jellyfish of the order or (later) subclass Discomedusae of scyphozoan cnidarians having a free-swimming, typically saucer-shaped or hemispherical medusa as the main stage in their life cycle.

adjective

Zoology
  • Of or relating to this order or subclass.

Origin

Late 19th century; earliest use found in The Century Dictionary. After scientific Latin Discomedusae, order name.