"Ice giant" refers to a type of planet with a thick, icy atmosphere and a relatively small, rocky core. It's a term commonly used to describe two planets in our solar system, Uranus and Neptune. However, there are several synonyms for the term "ice giant". Some people may refer to these planets as "icy giants" or "gas giants", though the latter term could also refer to Jupiter and Saturn. Other synonyms may include "frosty giants", "frozen giants", or "sub-Neptunes". Regardless of which term is used, these planets remain intriguing objects of study for astronomers and planetary scientists alike.