From Longman Dictionary of Contemporary EnglishPlutoPlu‧to /ˈpluːtəʊ $ -toʊ/ noun HAan object that goes around the Sun, usually beyond Neptune, which was called a planet until 2006 the discovery of Pluto in 1930
Examples from the Corpus
Pluto• On March 20 and October 9, Saturn and Pluto cross swords for the first time in two decades.• Added to this came the discovery of yet another planet - Pluto - in 1932. 