||Noc`ti*lu"ca (?), n.; pl.
NoctilucÆ (#). [L. noctiluca something
that shines by night, fr. nox, noctis, night +
lucere to shine, lux light.] 1. (Old
Chem.) That which shines at night; -- a fanciful name for
phosphorus.
2. (Zoöl.) A genus of marine
flagellate Infusoria, remarkable for their unusually large size and
complex structure, as well as for their phosphorescence. The
brilliant diffuse phosphorescence of the sea is often due to myriads
of Noctilucæ.