environmentalist Syllabification: (en·vi·ron·men·tal·ist)Pronunciation: /enˌvīrənˈmen(t)l-ist, -ˌvī(ə)rn-/Translate environmentalist | into German | into Italian Definition of environmentalist noun 1a person who is concerned with or advocates the protection of the environment. 2a person who considers that environment, as opposed to heredity, has the primary influence on the development of a person or group. Derivatives environmentalism noun environmentalist in other Oxford dictionaries Definition of environmentalist in the British & World English dictionary