An environmentalist is someone who works to protect the environment. This can include activities such as conservation, pollution control, and sustainability. The two crossword solutions for this term are ECOLOGIST (9 letters) and GREEN (5 letters). An ECOLOGIST is a scientist who studies the relationships between organisms and their environment. They study how organisms interact with each other and their environment, and how these interactions affect the environment. A GREEN person is someone who is environmentally conscious and takes action to reduce their environmental impact. They may practice sustainable living, use renewable energy sources, and advocate for environmental protection.