jellyfish

Any of numerous usually free-swimming marine cnidarians of the class Scyphozoa, characteristically having a gelatinous, tentacled, often bell-shaped medusa stage as the dominant phase of its life cycle.

Any of various similar or related cnidarians.

One who lacks force of character; a weakling.

A popular name of many kinds of acalephs, medusas, sea-blubbers, or sea-nettles: so called from the soft, gelatinous structure.

Any one of the acalephs, esp. one of the larger species, having a jellylike appearance. See medusa and acaleph.

Almost transparent aquatic being; any one of the acalephs, especially one of the larger species, having a jellylike appearance.

any of numerous usually marine and free-swimming coelenterates that constitute the sexually reproductive forms of hydrozoans and scyphozoans

large siphonophore having a bladderlike float and stinging tentacles