Source : Webster's Revised Unabridged Dictionary (1913)

Noctiluca \Noc`ti*lu"ca\, n.; pl. {Noctiluc[AE]}. [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. (Zo["o]l.) 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 Noctiluc[ae].

Source : WordNet®

noctiluca
     n : large bioluminescent marine protozoan [syn: {Noctiluca
         miliaris}]
     [also: {noctilucae} (pl)]

noctilucae
     See {noctiluca}