1. One of the five members of the planet-saving team in the animated series "Captain Planet and the Planeteers
" who is given a special ring that grants power over one of five elements (i.e. earth, fire, wind, water, and heart) and the ability to summon Captain Planet
when the power of his/her ring is combined with the powers of the other four ring-bearers.
2. Any person who works to help a planet ecologically (e.g. prevents pollution, conserves energy and natural resources, recycles, etc.).