Pyrosome
Pronunciation : Pyr"o*some
Part of Speech : n.
Etymology : [Pyro- + -some body.] (Zo?l.)
Definition : Defn: Any compound ascidian of the genus Pyrosoma. The pyrosomes form large hollow cylinders, sometimes two or three feet long, which swim at the surface of the sea and are very phosphorescent.
Source : Webster's Unabridged Dictionary, 1913