obe·​lia | \ ō-ˈbēl-yə How to pronounce obelia (audio) \

Definition of obelia

: any of a genus (Obelia) of small colonial marine hydroids with colonies branched like trees

First Known Use of obelia

1868, in the meaning defined above

History and Etymology for obelia

borrowed from New Latin, genus name, probably from Greek obelós "spit, four-sided pillar" + New Latin -ia -ia entry 1 — more at obelus

Note: Name introduced by the French naturalist François Péron (1775-1810) and the naturalist and artist Charles Alexandre Lesueur (1778-1846) in "Tableau des caractères génériques et spécifiques de toutes les espèces des Méduses connues jusqu'à ce jour," Annales du Muséum d'histoire naturelle, tome 14 (1809), p. 355. The authors give no indication of the name's etymology, though they refer to a conical appendage at the apex of the medusa's body ("un appendice conique au sommet de l'ombrelle") that may be the obelós in question.

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The first known use of obelia was in 1868

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