neptune

prop. 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. [ 1913 Webster ]

2. (Astron.) The remotest major planet of our solar system, discovered -- as a result of the computations of Leverrier, of Paris -- by Galle, of Berlin, September 23, 1846. It is classed as a gas giant, and has a radius of 22, 716 km and an estimated mass of 1.027 x 1026 kg, with an average density of 2.27 g/cc. Its mean distance from the sun is about 5, 000, 000, 000 km (3, 106, 856, 000 miles), and its period of revolution is about 164.78 years. [ 1913 Webster +PJC ]

Neptune powder, an explosive containing nitroglycerin, -- used in blasting. --
Neptune's cup (Zool.), a very large, cup-shaped, marine sponge (Thalassema Neptuni). [ 1913 Webster ]