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1. A giant planet with a ring of ice particles; the 8th planet from the sun is the most remote of the gas giants
   "the existence of Neptune was predicted from perturbations in the orbit of Uranus and it was then identified in 1846"
    
2. (Roman mythology) god of the sea; counterpart of Greek Poseidon

Derived forms: Neptunes

Type of: gas giant, Jovian planet, outer planet, Roman deity, superior planet

Part of: solar system

Encyclopedia: Neptune, West Virginia