Pronunciation: (en-vī"run-men'tl-ist, -vī"urn-),[key] —n. 1. an expert on environmental problems.
2. any person who advocates or works to protect the air, water, animals, plants, and other natural resources from pollution or its effects.
3. a person who believes that differences between individuals or groups, esp. in moral and intellectual attributes, are predominantly determined by environmental factors, as surroundings, upbringing, or experience (opposed to hereditarian).