\Nep"tune\, n. [L. Neptunus.]
1. (Rom. Myth.) The son of Saturn and Ops, the god of the
   waters, especially of the sea. He is represented as
   bearing a trident for a scepter.
2. (Astron.) The remotest known planet of our system,
   discovered -- as a result of the computations of
   Leverrier, of Paris -- by Galle, of Berlin, September 23,
   1846. Its mean distance from the sun is about
   2,775,000,000 miles, and its period of revolution is about
   164,78 years.
{Neptune powder}, an explosive containing nitroglycerin, --
   used in blasting.
{Neptune's cup} (Zo["o]l.), a very large, cup-shaped, marine
   sponge ({Thalassema Neptuni}).