ice giant

noun2

1. •
   A giant planet composed mostly of astronomical ices (condensed forms of volatile compounds) including water, methane, oxygen, carbon, nitrogen, and sulfur, and smaller than a gas giant. (e.g. Neptune and Uranus)

   • The fifth planet was an unknown, an ice giant in a drunken skewed orbit that took it from just inside the Jovian's orbit almost out to the sixth planet's. — 1976
2. •
   A frost giant.

   • The drops became living by the power of him who had sent the wind ; and from them sprang Ymir, the ice-giant. — 1832